MR imaging of lumbar juxtaarticular cysts.
Three surgically proven cases of lumbar extradural juxtaarticular cysts were examined by magnetic resonance (MR) imaging. The highly variable MR signal patterns are presented.
Adult↗
Biomedical subjects
K R Smith
Publications and source records attributed to K R Smith.
Fat deposition adjacent to chronic subdural hematoma: CT demonstration.
Computed tomography of the head in a patient with bilateral chronic subdural hematomas demonstrated areas of fat density closely approximating the hematomas. The persistent fatty nature of the CT finding was confirmed by subsequent magnetic resonance and CT performed 1 month and 3 years later. Although an intracerebral hemorrhage with transient presence of fatty material has been described in an alcoholic hyperlipemic patient, this case shows fatty deposition adjacent ot subdural hemorrhage without any known predisposing factors.
Adipose Tissue↗
Unusual hemorrhage with use of synthetic dural substitute: MR findings.
Delayed hemorrhage is an unusual complication of silastic dural substitute that can have a prolonged latent period. Two such patients that presented 6 and 12 years following surgery and that were evaluated by MR imaging are reported.
Cerebral Hemorrhage↗
MRI of marked dural sac compression by surgicel in the immediately postoperative period after uncomplicated lumbar laminectomy.
PURPOSE: Our purpose was to determine what represents normal findings on MR examinations of the lumbar spine in the immediately postoperative period following lumbar laminectomy with retained Surgicel. METHOD: MR examinations were performed immediately following lumbar laminectomy in 10 patients referred for symptoms of spinal stenosis. All had Surgicel retained against the dura and were doing well postoperatively without suggestion of adverse symptoms. Images were obtained within 4 days of surgery, most within 24 h. RESULTS: In 9 of 10 patients, severe dural tube compression was present, greater than that evident on preoperative studies. CONCLUSION: Marked spinal canal compression can be a normal finding in the immediately postlaminectomy period in patients with retained Surgicel. There is a lack of correlation between apparent mass effect on the thecal sac and adverse effect. The MR appearance in such instances is not significant in the absence of compressive clinical symptomatology.
Adipose Tissue↗
Osteoid-producing orbital ethmoid tumor.
Fibro-osseus lesions of the paranasal sinuses, especially those that contain multinucleated giant cells, demonstrate a significant histopathologic overlap although they manifest themselves throughout a wide range of clinical behavior. They routinely require a critical clinical and pathologic interpretation. Often, the clinical course of the disease is the only guide to diagnosis and mode of treatment. This study presents the case of a 4-year-old boy with an osteoid-producing tumor of the ethmoid sinus. Despite an original diagnosis of fibrous dysplasia, the lesion followed a relentless course. Eventually, maxillectomy, orbital exenteration, and craniotomy were required to control the disease. The literature of fibro-osseous lesions of the paranasal sinuses is reviewed and an attempt is made to classify these lesions according to their clinical behavior.
Child, Preschool↗
Household firewood use and the health of children and women of Indian communities in Chiapas, Mexico.
A follow-up study in two rural communities in the state of Chiapas, Mexico, compared families that used an improved stove for cooking with those that used traditional open-fire stoves, to assess the risks of respiratory symptoms in children and women exposed to wood smoke. 16-hour measurements showed that the concentration of particles less than 10 microm in diameter was significantly lower in households with the better stoves in the kitchen area, where children usually play, i.e., 158 microg/m3 vs 305 microg/m3 (p = 0.03). Multivariate models showed that using the better stove tended to protect against symptoms such as the common cold in children (RR 0.24; 9.5% CI 0.05, 1.02). Use of more firewood was linked to greater risks of experiencing difficulty breathing (RR 1.15; 95% CI 1.04, 1.27) and the common cold (RR 1.09; 95% CI 1.01, 1.18) in women. The use of stoves that require less wood for cooking reduces the risks of respiratory symptoms that may contribute to complicated respiratory diseases and mortality.
Adolescent↗
Head injury, an empirical study: describing long-term productivity and independent living outcome.
As part of larger, multivariate study to be reported later, the present research gathered data from a knowledgeable informant, via telephone, concerning productivity and independent living outcomes for 75 subjects who sustained varying degrees of head injury, 4-7 years prior to the follow-up. The severity of the injury was measured using the Glasgow Coma Scale. Eighteen subjects had a severe injury, 24 had a moderate injury and 33 had a mild injury. The outcomes researched included indices of the subjects' ability to live independently and to be productive. In general, the data indicate that the more severe the injury, as measured by the best GCS during the first 24 hours, the more dependent and less productive the subject was at follow-up. This, however, was not invariably the case. Several mildly injured subjects had poor outcomes, while several severely injured subjects had relatively good outcomes at follow-up.
Activities of Daily Living↗
Head injury, a multivariate study: predicting long-term productivity and independent living outcome.
As the second of a two-part research project, this study attempted to build three clinically useful prediction equations; these equations would be used to predict three long-term functional outcomes: productivity status, living arrangement status, number of hours of assistance required per week. There were ten predictor variables used in each analysis. These ten variables belonged to four theoretical classes: pre-injury demographics, pre-injury social characteristics, severity of injury, and post-injury environmental variables. The analytical method used was the General Linear Model of multiple regression, rather than the most often used Stepwise regression procedure. The results indicate that in none of the three prediction equations was more than 28% of the criterion variance accounted for, and only a minority of the predictor variables were significant predictors. It is concluded that, while the equations are of only very limited utility, the theoretical model and the analytical technique will be useful for future investigators.
Activities of Daily Living↗
Temporal-frequency tuning of cross-orientation suppression in the cat striate cortex.
A sinusoidal mask grating oriented orthogonally to and superimposed onto an optimally oriented base grating reduces a cortical neuron's response amplitude. The spatial selectivity of cross-orientation suppression (XOR) has been described, so for this paper we investigated the temporal properties of XOR. We recorded from single striate cortical neurons (n = 72) in anesthetized and paralyzed cats. After quantifying the spatial and temporal characteristics of each cell's excitatory response to a base grating, we measured the temporal-frequency tuning of XOR by systematically varying the temporal frequency of a mask grating placed at a null orientation outside of the cell's excitatory orientation domain. The average preferred temporal frequency of the excitatory response of the neurons in our sample was 3.8 (+/- 1.5 S.D.) Hz. The average cutoff frequency for the sample was 16.3 (+/- 1.7) Hz. The average preferred temporal frequency (7.0 +/- 2.6 Hz) and cutoff frequency (20.4 +/- 6.9 Hz) of the XOR were significantly higher. The differences averaged 1.1 (+/- 0.6) octaves for the peaks and 0.3 (+/- 0.4) octaves for the cutoffs. The XOR mechanism's preference for high temporal frequencies suggests a possible extrastriate origin for the effect and could help explain the low-pass temporal-frequency response profile displayed by most striate cortical neurons.
Animals↗
The nuclear trial sign in thoracic herniated disks.
PURPOSE AND METHODS: Postmyelography CT studies of 84 patients with 114 thoracic herniated disks were reviewed for endplate irregularity, sclerosis, and/or disk-space calcification that could suggest a migratory path of the herniated fragment. RESULTS: Abnormal straight or curvilinear densities (the "nuclear trial sign") were present at the level of the disk or endplate in 46% of the cases. MR studies of 35 thoracic herniated disks were also examined. Similar changes were likewise present in 44%. CONCLUSION: The frequent occurrence of this finding in the mid and lower thoracic spine renders it a useful secondary sign for thoracic herniated disks, although false positives do occur.
Humans↗
Results of a national survey of physicians' knowledge and application of prevention capabilities.
We used the Comprehensive Prevention Knowledge and Applications Survey Instrument to study health promotion and disease prevention activities of a national sample of 777 family physicians. The study demonstrated active counseling in some areas, such as smoking cessation, but lesser efforts in other aspects, including counseling about smokeless tobacco cessation, seat belt use, sunlight exposure, prevention of AIDS and other sexually transmitted diseases, and preconceptual counseling. Although respondents thought themselves prepared to counsel about prevention efforts, they reported limited success in changing patients' behavior. The physicians documented frequent application of many prevention techniques, and they noted much more frequent use of mammography than has been reported in prior studies. The survey results indicate the need for modification of medical education programs and for enhancement of ability to change behavior to reduce health risks.
Acquired Immunodeficiency Syndrome↗
The Comprehensive Prevention Knowledge and Applications Survey Instrument: its validity and reliability.
Because the instruments used to measure current practices among primary care physicians in a broad range of prevention activities are limited, we developed a study to test a tool that would evaluate current prevention knowledge and applications, including items regarding activities to prevent AIDS and other sexually transmitted diseases. The Comprehensive Prevention Knowledge and Applications Survey Instrument measures knowledge, counseling capabilities, and use of recommended applications in preventive medicine. We designed and tested a 74-item instrument. Four recognized experts in preventive medicine and public health determined its content validity. We then proceeded with reliability testing with a random sample of 315 family physicians and replicated it with an additional 432 physicians for stability reliability. Internal consistency reliability and stability reliability have both been demonstrated for this instrument.
Health Knowledge, Attitudes, Practice↗
A survey of physicians' knowledge and application of AIDS prevention capabilities.
Currently, no effective immunization prevents AIDS and no curative treatment exists for the AIDS patient. However, sufficient knowledge of the pathophysiology of this disease exists to prevent its spread. Effective application of this capability requires that health care providers secure and apply this knowledge. This study reports the results of a national survey of family physicians' knowledge and application of AIDS prevention capabilities. The Comprehensive Prevention Knowledge Applications Survey Instrument was used for the survey. It revealed that, in contrast to other prevention activities, respondents (n = 765) reported low use of practices important in AIDS prevention. For example, only 18% routinely obtain sexual histories from patients seen regularly, and, of those obtaining these histories, fewer than 20% routinely obtain information regarding high-risk activities. Over 40% do not routinely ask about homosexual activities, and almost 60% omit questions about intravenous drug use, even though the patient has symptoms suggesting AIDS in both instances. Methods of enhancing application of available capabilities may focus on expanded education and intervention activities.
Acquired Immunodeficiency Syndrome↗
Validity and reliability of a breast cancer knowledge test.
A study was made to develop and test a tool to measure a subject's knowledge about breast cancer screening in order to implement effective strategies for prevention and early detection. The Breast Cancer Knowledge Test measures a subject's knowledge about detection and screening practices. The instrument is an expansion of Stillman's Knowledge Questionnaire. A 30-item test was designed and pretested. Four nationally recognized experts in cancer control determined content validity. Reliability testing then was done with a sample of 101 women 50 years of age and older. The complete posttested 18-item instrument is reported here. Correlational analyses were done between the total scores on the Breast Cancer Knowledge test and subjects' practice of screening behaviors. Findings indicate that more knowledge of breast cancer screening is associated with use of mammography and obtaining a professional examination, but not with the practice of breast self-examination.
Aged↗
Percutaneous transluminal angioplasty prior to carotid cavernous fistula embolization.
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Adult↗
Balloon embolization of a traumatic carotid-ophthalmic pseudoaneurysm with control of the epistaxis and preservation of the internal carotid artery.
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Aneurysm↗
Allied health manpower strategies: estimates of the potential gains from efficient task delegation.
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Allied Health Personnel↗