Search PubMed⌕ Search

Biomedical subjects

J R Akin

Publications and source records attributed to J R Akin.

At least 19 recordsLinked to original sources
PubMed1985

Clinical superiority of a new nonionic contrast agent (iopamidol) for cardiac angiography.

The hemodynamic and electrophysiologic alterations induced by ionic contrast agents during cardiac angiography are well described. Recently nonionic contrast agents have become available for cardiac angiography. To evaluate the safety of these new agents, a double-blind randomized study was performed comparing a new nonionic agent (iopamidol) with a commonly used ionic contrast agent (Renografin-76). Eighty-one patients undergoing left ventriculography and coronary angiography were included; 41 received iopamidol and 40 received sodium meglumine diatrizoate (Renografin-76). After left ventriculography, there was a decrease in the arterial pressure with both contrast agents. However, the severity and the duration of hypotension were both significantly greater with Renografin-76 compared with the new nonionic agent (p less than 0.001). After selective injections of the coronary arteries, electrocardiographic analysis demonstrated that the increase in the QT interval (p less than 0.0002) and the changes in both the ST segment and T wave amplitude (p less than 0.001) were significantly greater in the Renografin-76 group compared with the iopamidol group. During coronary angiography, 8 of the 40 patients receiving Renografin-76 required temporary pacing for sinus pauses of 2.5 seconds or more, and 2 of the 40 also developed ventricular fibrillation. None of the 41 patients receiving iopamidol had these complications. This report demonstrates that the electrocardiographic changes, the severity and duration of hypotension and the incidence of serious arrhythmias are significantly greater with Renografin-76 than with iopamidol. Thus, this new nonionic agent appears to enhance the safety of cardiac angiography.

Aged↗
PubMed1985

Radiologists and informed-consent lawsuits.

A national survey on informed-consent lawsuits that resulted from studies using contrast material revealed that 123 (8%) of 1,513 radiologists surveyed or others in their groups had been involved in informed-consent lawsuits. In response to a detailed follow-up questionnaire, 67 radiologists anonymously provided additional information regarding their lawsuits, which most often involved excretory urography (37%) or angiography (38%), with death or neurologic impairment the most common patient injuries. As a result of these lawsuits, many radiologists provide more detailed information to patients. In the United States, the total number of informed-consent lawsuits, however, was small in relation to the total number of studies done using contrast material.

Angiography↗
PubMed1984

Informed consent for intravenous contrast-enhanced radiography: a national survey of practice and opinion.

A detailed questionnaire regarding the obtaining of patient consent for the administration of intravenous contrast agents was sent to 3845 radiologists in those hospitals across the United States having more than 100 beds. The results represent the current community practice and opinion of the 1547 radiologists (40%) who answered. They showed that 66% of respondents obtained no type of informed consent before injecting intravenous contrast agents. Half of those who did obtain consent did not inform their patients of possible specific major adverse reactions. Half of those who did not obtain consent believed the risk of adverse reaction was remote. Another 40% believed the consent procedure might heighten anxiety and, therefore, increase the risk of reaction. Obtaining informed consent, however, was not significantly associated with an increased incidence of major reactions. Since 8% of the respondents indicated some involvement in malpractice lawsuits regarding the question of informed consent for various procedures, the obtaining of informed consent might lessen the risk of exposure to malpractice litigation. Additional results showed that written consent did not appear to lessen the number of studies performed and that it offered more specific information to the patient regarding complications. Finally, most radiologists (80%) requested a specific policy regarding informed consent from at least one of the following organizations: the American College of Radiology (ACR) (96%), the Radiological Society of North America (RSNA) (26%), state chapters of the ACR (15%).

Attitude of Health Personnel↗
PubMed1982

Improved radiation protection for physicians performing cardiac catheterization.

Physicians and their assistants performing diagnostic angiography must be concerned with the radiation exposure they receive. The introduction of hemiaxial projections for imaging has increased diagnostic accuracy but has also greatly increased the physicians' exposure to scattered radiation. This increase is especially critical for the eyes and thyroid of the physician who routinely performs these procedures. To reduce such exposure a ceiling-suspended shield (60 x 45 cm), made of 6.4 mm glass with a 19.5 kg/m2 (4 lb/ft2) lead equivalency, was developed. During procedures the shield is interposed between the physician and the region of the patient acting as the source of scattered radiation. The degree of radiation protection to the operator was assessed by measuring the distribution of scattered radiation in the vicinity of the operator with and without the shield. The effectiveness of the shield was determined in the 30 degrees right anterior oblique (RAO), 5 degrees left anterior oblique (LAO), 35 degrees LAO, and 50 degrees LAO-15 degrees cranial angulations. At critical heights such as the level of the eyes and thyroid, scattered radiation levels were reduced by 85% or greater in all angulations. Without interfering with the physician's ability to observe the patient or manipulate the catheter, this shield can significantly reduce the physician's exposure to radiation.

Angiocardiography↗
PubMed1982

Amylase levels in the tissues and body fluids of several primate species.

1. Serum amylase levels in the gorilla, orang-utan, chimpanzee and squirrel monkey are similar to man. Serum amylase in the Rhesus macaque is almost a whole order of magnitude higher than man. 2. Of the several species tested, all have appreciable amylase in saliva or the parotid gland except the squirrel monkey. 3. High levels of amylase were found in the pancreas of all species tested. Amylase was found in the livers of all species tested. 4. In in vivo experiments with squirrel monkeys, injection of puromycin did not alter serum amylase levels.

Amylases↗
PubMed1982

Effects of systemic hyperthermia on the growth patterns of experimental neoplasms.

Hyperthermia has been shown to have a detrimental effect on experimental and human neoplasms. A water bath immersion system is described to evaluate the effects of systemic hyperthermia (SH) on the growth patterns of the Morris hepatoma 7777 in male Buffalo rats. SH and anesthesia were observed to have no long-term detrimental effects on weight trends or chow consumption. Inhibition of growth was demonstrated for this experimental tumor model at extreme SH (41.5 degree to 42.0 degree C), and it was statistically different (P less than 0.01) from the patterns of tumor growth observed in controls and tumor-burdened animals treated with moderate SH (39..5 degree to 40.0 degree C). Cessation of extreme SH resulted in acceleration of tumor growth so that no difference in tumor volume or animal survival was identified SH resulted in retardation of tumor growth patterns, but its effects were not sustained once treatments were stopped.

Animals↗
PubMed1980

Compensation examination of the cervical and lumbar spines: critical disagreement in radiographic interpretation.

Radiographic interpretation is often the major factor in the decision to award compensation for job-related complaints, especially in the Veterans Administration system. Three board-certified radiologists reviewed 200 consecutive lumbar and cervical spine examinations and assigned each case to one of three categories: normal, normal for age (not compensable), or degenerative disease (compensable). A critical disagreement, in which at least one radiologist considered the examination compensable and another not compensable, occurred in interpretation of 31% of the cervical and 46% of the lumbar spine examinations. Although the overall detection of radiographic findings was similar among all three radiologists, diagnostic interpretation of the findings varied greatly. Although most radiologists and orthopedists agree that the use of plain radiography of the spine as a deciding factor in awarding compensation is unjustified and inappropriate, until the regulations are changed there is a pressing need for strict, objective, radiographic criteria for determining "normal aging" of the cervical and lumbar spines so that interpreatations can be more uniform.

Adult↗
PubMed1980

Optimal use of portable and stat examination.

Using previously published criteria for "justification" of requests for portable and stat radiographs, a prospective study was instituted in a 300-bed teaching hospital. The rates of "unjustified" portable and stat examinations were 5% and 10%, respectively, significantly lower than in a previous study. The results indicate that close cooperation between radiologists and referring clinicians and proper education of house staff can result in more optimal use of these valuable, though often overused, techniques.

California↗
PubMed1980

Optimum radiographic examination for consideration of compensation awards: I. General methodology and application to chest examination.

A major goal of the radiologist is to devise methods to decrease health care costs and radiation exposure without sacrificing diagnostic accuracy. In a large Veterans Administration (VA) hospital, a prospective study was undertaken to determine the optimum number of radiographic projections needed to assess applicants for VA compensation for chest disease or injury claimed to be service-related. Three separate readings of every chest radiographic assessment could have been made from a single posteroanterior view. In eight cases, granulomas or mild hyperexpansion of the lungs were only appreciated using the lateral projection, but these findings were not clinically significant and did not affect decisions as to whether compensation sould be awarded. The only potentially serious lesion missed (a possible pulmonary nodule) using the posteroanterior view alone was also missed using the lateral and only suggested by the oblique views. Extrapolating these results to data on compensation examinations performed in the entire VA system (fiscal year 1978), it was concluded that limiting the radiographic examination of the chest to a single posteroanterior view would eliminate 150,000 radiographs in the evaluation of 190,000 applicants and yield an annual savings of almost $900,000.

Accidents, Occupational↗
PubMed1980

Optimum radiographic examination for consideration of compensation awards: II. Cervical and lumbar spines.

In a large Veterans Administration (VA) hospital, a prospective study was undertaken to determine the optimum number of radiographic projections needed to assess applicants for VA compensation for cervical and lumbar spine disease or injury claimed to be service-related. Results show that the final radiographic assessment could be made in 100% (245) of cervical spine examinations using two views (anteroposterior and lateral) and in 99.3% (699/704) of lumbar spine examinations using two views (anteroposterior and a single well centered lateral). Extrapolating these results to data on compensation examinations performed in the entire VA system (fiscal year 1978), it was concluded that limiting the radiographic examinations of the cervical and lumbar spines to these views would eliminate 193,000 radiographs in the evaluation of 100,000 applicants and yield an annual savings of about $1,000,000.

Accidents, Occupational↗
PubMed1980

Optimum radiographic examination for consideration of compensation awards: III. Knee, hand and foot.

In a large Veterans Administration (VA) hospital, a prospective study was undertaken to determine the optimum number of radiographic projections needed to assess applicants for VA compensation for knee, hand, and foot diseases or injury claimed to be service-related. Results show that the final radiographic assessment could be made in all 535 (100%) of the knee examinations using two views (anteroposterior and lateral), all 181 (100%) of the hand examinations using one view (anteroposterior), and all 223 (100%) of the foot examinations using two views (anteroposterior and lateral). Extrapolating these results to data on compensation examinations performed in the entire VA system (fiscal year 1978), it was concluded that limiting the radiographic examinations of the knee, hand, and foot to these views would eliminate 91,000 radiographs in the evaluation of 119,000 applicants and yield an annual savings of about $500,000.

Accidents, Occupational↗
PubMed1979

Amylase levels in the tissues and body fluids of the domestic cat (Felis catus).

1. The amylase activities of serum, liver, pancreas, submaxillary and parotid glands, saliva, duodenum, colon, lung, heart, spleen, kidney and skeletal muscle of the domestic cat, were determined. 2. As in most mammals, the highest amylase content was found in the pancreas. Levels in saliva and salivary glands were very low. 3. Amylase activities of the serum, liver and pancreas have an optimum pH 7.0-7.5. 4. Amylases of serum, liver and pancreas were inactivated by removal of chloride and these activities mainly restored by addition of chloride.

Amylases↗
PubMed1979

Single, well centered lateral view of lumbosacral spine: is coned view necessary?

A single lateral view, centered 1 cm above the top of the palpable iliac crest, has been shown to adequately demonstrate the entire lumbar spine and lumbosacral junction in over 90% of patients, thereby eliminating the necessity to obtain both a full lateral and coned lateral view of the lumbosacral junction. Eliminating this extra film from the routine lumbosacral examination results in enormous savings in patient cost and patient radiation exposure, without sacrificing any diagnostic accuracy.

Humans↗