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Biomedical subjects

S F Johnson

Publications and source records attributed to S F Johnson.

At least 19 recordsLinked to original sources
PubMed2001

Practice parameters for the use of laser-assisted uvulopalatoplasty: an update for 2000.

Laser-assisted uvulopalatoplasty (LAUP) is an outpatient surgical procedure which is in use as a treatment for snoring. LAUP also has been used as a treatment for sleep-related breathing disorders, including obstructive sleep apnea. The Standards of Practice Committee of the American Academy of Sleep Medicine reviewed the available literature, and developed these practice parameters as a guide to the appropriate use of this surgery. Adequate controlled studies on the LAUP procedure for sleep-related breathing disorders were not found in peer-reviewed journals. This is consistent with findings in the original practice parameters on LAUP published in 1994. The following recommendations are based on the review of the literature: LAUP is not recommended for treatment of sleep-related breathing disorders. However, it does appear to be comparable to uvulopalatopharyngoplasty (UPPP) for treatment of snoring. Individuals who are candidates for LAUP as a treatment for snoring should undergo a polysomnographic or cardiorespiratory evaluation for sleep-related breathing disorders prior to LAUP and periodic postoperative evaluations for the development of same. Patients should be informed of the best available information of the risks, benefits, and complications of the procedure.

Humans↗
PubMed2001

Practice parameters for the treatment of narcolepsy: an update for 2000.

Successful treatment of narcolepsy requires an accurate diagnosis to exclude patients with other sleep disorders, which have different treatments, and to avoid unnecessary complications of drug treatment. Treatment objectives should be tailored to individual circumstances. Modafinil, amphetamine, methamphetamine, dextroamphetamine, methylphenidate, selegiline, pemoline, tricyclic antidepressants, and fluoxetine are effective treatments for narcolepsy, but the quality of published clinical evidence supporting them varies. Scheduled naps can be beneficial to combat sleepiness, but naps seldom suffice as primary therapy. Regular follow up of patients with narcolepsy is necessary to educate patients and their families, monitor for complications of therapy and emergent of other sleep disorders, and help the patient adapt to the disease.

Humans↗
PubMed1998

Wilms' tumor with renal cell carcinoma overgrowth in a 3-year-old child.

Wilms' tumors that contain features of both renal cell carcinoma and classic Wilms' tumor histology are rare. Even though nine such cases have been previously reported in the literature, we report the first case of a Wilms' tumor with an overwhelmingly renal cell carcinoma histologic pattern.

Carcinoma, Renal Cell↗
PubMed1995

Histopathology of fetal diastrophic dysplasia.

We report on three cases of diastrophic dysplasia in second trimester fetuses and discuss the differential diagnosis and clinical, radiologic, and histopathologic findings. Manifestations of typical diastrophic dysplasia in infants and older patients include abnormal pinnae, scoliosis, and joint contractures; these were absent in the fetuses, in keeping with the tendency for the clinical and radiologic aspects of this disease to become more severe with age. The histopathologic characteristics of the cartilage appear to be similar in the fetus and older patient, and therefore may be useful in differentiating diastrophic dysplasia from other osteochondrodysplasias in the second trimester.

Cartilage↗
PubMed1993

Diagnosis by electroencephalographic topography.

In 5 patients, electroencephalographic (EEG) topography (Fourier analysis and topographic display of EEG data) demonstrated clinically significant acute brain lesions not seen by magnetic resonance imaging or computed tomography. EEG topography contributed to patient management more than standard EEG. Additional, carefully designed, prospective studies may indicate how frequently and in which settings EEG topography is a valuable diagnostic test.

Adult↗
PubMed1993

Lymphangioleiomyomatosis.

Lymphangiomyomatosis (LAM) is a progressive disease afflicting women of childbearing age. LAM remains a rare disease, unfamiliar to many clinicians. It usually poses a diagnostic dilemma for the primary physician, possibly resulting in a delayed or missed diagnosis, unnecessary operative intervention, and inappropriate therapy. LAM is characterized microscopically by abnormal smooth muscle proliferation causing gradual obstruction of small airways, lymphatics, and vasculature. The proliferation eventually results in a characteristic clinical syndrome of progressive dyspnea, recurrent pneumothorax, chylous effusion, and hemoptysis. Despite a variety of treatment regimens developed since the first description of LAM, patient survival has not improved appreciably. Most patients die within 10 years of the time of diagnosis. This report presents a patient with LAM and a review of the literature.

Adult↗
PubMed1991

Tetrasomy of the short arm of chromosome 9: prenatal diagnosis and further delineation of the phenotype.

A fetus with multiple malformations was identified by prenatal ultrasound investigation. Cordocentesis and fetal lymphocyte chromosome analysis demonstrated a model number of 47 chromosomes. The extra chromosome material was identified as an isochromosome of the entire short arm of chromosome 9 with no involvement of the heterochromatic region of the long arm [47,XY, + i(9p)]. This represents the first report of prenatal diagnosis of tetrasomy 9p. Further delineation of the phenotype is discussed.

Aneuploidy↗
PubMed1991

Brachial plexus injury: association with subclavian and axillary vascular trauma.

Proximal upper extremity (subclavian and axillary) vascular injury (SAVI) and brachial plexus injury (BPI) occur uncommonly. However, BPI may be associated with SAVI and frequently is an important determinant of long-term disability. The medical records of patients with traumatic SAVI, BPI, or both over a 5-year period were reviewed. A total of 31 patients were identified. The group was predominantly male (28 men/3 women) with a mean age of 30.5 +/- 1.8 years (range, 15-63 years). Blunt trauma accounted for 43.5% of SAVI cases and 77.8% of BPI cases. Thirteen patients (41.9%) sustained SAVI alone (group I), 10 patients (32.2%) had combined SAVI and BPI (group II), and 8 patients (25.9%) had BPI alone (group III). Subclavian and axilliary vascular injury occurred in 10 of 18 patients (55.6%) with a BPI. Brachial plexus injury occurred in 10 of 23 patients (43.5%) with a SAVI. Patients with SAVI from blunt trauma were significantly more likely to have an associated complete BPI than patients with penetrating trauma. All patients with a complete BPI (6 patients) had an associated SAVI regardless of mechanism of injury. Only one patient with a partial BPI from blunt trauma had an associated SAVI. The Injury Severity Score was significantly higher for patients in group II. An average of 2.8 and 3.3 associated injuries were observed in patients with SAVI (groups I and II) versus patients without SAVI (group III), respectively. No patient who had a complete BPI showed an improvement in neurologic status during a mean follow-up of 7.2 months. No late vascular sequelae occurred in group-III patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Changes in alcohol, cigarette, and recreational drug use during pregnancy: implications for intervention.

From the Baltimore-Washington Infant Study, a regional epidemiologic study of congenital cardiovascular malformations, 1,336 mothers of infants selected as controls (a representative sample of the area birth cohort enrolled between April 1, 1981 and September 1, 1984) were studied with respect to alcohol, cigarette, and recreational drug use prior to and during pregnancy. Nearly half of the 1,336 women abstained from any substance use during pregnancy. Of the remainder, half restricted substance use to only alcohol or cigarettes. Only cigarette smokers showed a majority (68.5%) of women failing to successfully quit during pregnancy. Cigarette and recreational drug use during pregnancy was associated with lower socioeconomic status, while alcohol use was associated with higher social status. Cessation of cigarette and recreational drug use was more common among professionals and the college-educated, but these same characteristics, along with higher income, were associated with failure to quit drinking. Younger women were less likely to use alcohol and cigarettes and more likely to successfully quit these habits once adopted. Use of alcohol and tobacco was greater among whites, and recreational drug use was greater among black women, but race was not associated with quitting use of any substance. Length of time trying to become pregnant and the mother's perceived health were not found to be associated with substance use or quitting. This sociodemographic profile suggests subgroups which must be targeted for intervention by the prenatal care provider, as well as intervention strategies.

Adolescent↗
PubMed1987

Juvenile xanthogranuloma underneath a toenail.

A 1 1/2-year-old boy developed a dystrophic toenail shortly after trauma to the foot. At the age of three years, it was recognized that the nail deformity was caused by a subungual tumor. The tumor proved to be a juvenile xanthogranuloma. The lesion was solitary, and no systemic associations or visceral involvement were found.

Child, Preschool↗
PubMed1985

The importance of the alpha-adrenoceptor agonist activity of dobutamine to inotropic selectivity in the anaesthetized cat.

Doses of dobutamine (steady-state infusions) required to increase inotropy (as measured by isovolumic indices of contractility) were lower than those required to produce tachycardia in the anaesthetized cat. When compared to isoprenaline, dobutamine produced less tachycardia for common increases in inotropy and thus demonstrated inotropic selectivity in this model. Dobutamine also produced mild pressor effects which were potentiated by beta-adrenoceptor blockade with propranolol. In efforts to define the role of the partial agonist activity of dobutamine for alpha-adrenoceptors in the production of selective inotropy the effects of dobutamine infusions were observed in cats pretreated with the alpha-adrenoceptor antagonist phentolamine. In phentolamine-treated cats dobutamine did not demonstrate inotropic selectivity and showed a relationship between increased inotropy and tachycardia which was not significantly different from that obtained with isoprenaline. In contrast, phentolamine did not change the relationship between isoprenaline-induced tachycardia and increased inotropy. These data suggest that the agonist activity of dobutamine for alpha-adrenoceptors could be responsible for selective inotropy in the anaesthetized cat probably by baroreceptor-mediated reflex modulation of heart rate and/or possible stimulation of inotropic cardiac alpha-adrenoceptors.

Animals↗
PubMed1985

Physician-patient communication. Understanding congenital heart disease.

Mothers' descriptions of their childrens' congenital heart disease were compared with cardiologists' diagnoses. Maternal understanding was examined with respect to 21 factors using bivariate contingency tables and multiple regression analyses. Of 285 mothers, 36% demonstrated poor comprehension. Maternal understanding was associated with sociodemographic variables but not with factors related to stress. All variables taken in concert that were predictive of understanding explained less than 13% of the variability in maternal knowledge. Distorted perceptions of congenital heart disease may cause unnecessary anxieties, inappropriate restrictions, and impairment of the child's self-perception. The bizarre nature of some of the mothers' incorrect descriptions and the accuracy of responses of mothers in biologic and health care occupations suggest that fundamental ignorance of the cardiovascular system may be of such importance as to minimize the impact of other variables.

Attitude to Health↗
PubMed1985

Somatosensory evoked potentials in abetalipoproteinemia.

Visual, brain-stem auditory, and somatosensory evoked potentials (SEPs) were obtained on a patient with known abetalipoproteinemia. Only the SEP was abnormal, and it correlated with the reported neuropathology of this disease. Serial SEP studies remained stable, as had the clinical condition of this patient on vitamin E therapy. The SEP may supplement clinical examination in follow-up of patients under treatment.

Abetalipoproteinemia↗
PubMed1983

Giant cell tumor of the sphenoid bone.

A case of giant cell tumor of the sphenoid bone is reported, the first case in which a computed tomogram is available. The radiologic features of the neoplasm resembled both pituitary adenoma and parasellar meningioma, but with more bone destruction. It is appropriate to consider this lesion in the differential diagnosis of a parasellar mass in a teenage or young adult patient when extensive bone destruction is present.

Adolescent↗