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Biomedical subjects

J H Ferguson

Publications and source records attributed to J H Ferguson.

At least 19 recordsLinked to original sources
PubMed1995

The NIH consensus development program.

The NIH CDCs are a highly visible, public forum to evaluate controversial medical technologies by synthesizing current medical science data. The consensus statements, although not intended as medical practice guidelines, may form part of the database preceding guideline formulation. It is difficult to assess the effect of the conferences on physician practice, in part reflecting the interference of the many other influences, medical and nonmedical, on physician behavior. Yet the program has had some success in influencing reimbursement policy for some technologies here and abroad and in influencing specialty organization policy, thereby indirectly affecting physician behavior. On the other hand, OMAR's dissemination activities have apparently been so successful that demand for CDC statements has more than doubled over the past five years, prompting OMAR to establish an information service (including fax and the Internet). And finally, the program has spawned consensus conferences throughout the world, including Canada, Western Europe, and Israel (Goodman & Baratz 1990).

Consensus Development Conferences, NIH as Topic↗
PubMed1994

Ambulatory blood pressure monitoring during pregnancy. Establishment of standards of normalcy.

Ambulatory blood pressure monitoring (ABPM) was used as an effective methodology by a primary care physician to assess normalcy of blood pressure (BP) and heart rate during pregnancy. One hundred fifty pregnant women in one of three periods (18 to 22, 30 to 32, and 36 to 38 weeks) of gestation and 30 age-matched nonpregnant women participated in this study. The study was designed to establish ABPM standards of normalcy during critical times of gestation. Twenty-four-hour BP (systolic and diastolic BP) values monitored during gestational weeks 18 to 22 and 30 to 32 were similar to each other and lower than the same values recorded in nonpregnant women. Blood pressures monitored during gestational weeks 36 to 38 were significantly higher than similar values observed during the two earlier gestational periods but not significantly higher than nonpregnancy BP values. Heart rates were significantly elevated during all gestational periods when compared with nonpregnancy heart rates. The results of this study established normalcy BP curves during three different gestational periods. Mean 24-h, daytime, and nighttime BPs were significantly elevated during weeks 36 to 38 when compared with BPs recorded during gestational weeks 18 to 22 and 30 to 32. Ambulatory blood pressure monitoring is a useful tool for the measurement and treatment of BP abnormalities during pregnancy.

Adolescent↗
PubMed1992

The Consensus Development Program. Detecting changes in medical practice following a consensus conference on the treatment of prostate cancer.

The treatment of prostate cancer was reviewed at a U.S. National Institutes of Health Consensus Development Conference in June 1987. Data from the U.S. National Cancer Institute's Surveillance, Epidemiology, and End Results tumor registries were analyzed and showed that the proportion of eligible prostate cancer patients receiving the recommended therapies did not increase at a faster rate after the conference than before.

Aged↗
PubMed1990

Analysis of the National Institutes of Health Medicare coverage assessment.

The National Institutes of Health (NIH) is periodically asked to conduct assessments of new medical technologies to assist in coverage decisions made at the Office of Health Technology Assessment (OHTA) for the Health Care Financing Administration coverage policy. Analysis of NIH assessments indicates that even though most NIH assessments rely only on expert opinion, OHTA agreed with NIH recommendations in over 90%.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1984

Oxygen storage capacity and tolerance of submergence of a non-aquatic reptile and an aquatic reptile.

The oxygen storage capacities and the tolerance to submergence of an aquatic snake, Natrix sipedon, and a non-aquatic snake, Crotalus viridis, were determined and compared. C. viridis was found to have a larger oxygen storage capacity, hemoglobin content and blood volume than N. Sipedon. The submergence time for C. viridis was 30.13 min which was less than the estimated time for submergence based on the oxygen storage capacity. N. sipedon exceeded its estimated dive time of 24.00 min and remained submerged for 65.57 min without signs of stress. During submergence, the heart rate of N. sipedon fell to 9% (5 beats/min) of the resting rate, while the heart rate of C. viridis fell to only 75% (27 beats/min) of the resting rate during this activity. These data indicate that N. sipedon responds to submergence via a typical diving reflex and extends its oxygen stores beyond that expected of a non-diver such as C. viridis.

Animals↗
PubMed1984

Scaling the physiological effects of exposure to radiofrequency electromagnetic radiation: consequences of body size.

We have demonstrated that a comparative analysis of the physiological effects of exposure of laboratory mammals to radiofrequency electromagnetic radiation (RFR) may be useful in predicting exposure thresholds for humans if the effect is assumed to be due only to heating of tissue. The threshold specific absorption rate (SAR) necessary to affect a thermoregulatory parameter shows an inverse and linear relationship to body mass. The inverse relationship between threshold SAR and body mass is attributed to a surface area: body mass relationship. In comparison to small mammals, relatively large mammals have a reduced capacity to dissipate an internal heat load passively, and are therefore physiologically more sensitive to RFR exposure. The threshold for a thermoregulatory response depends on the type of response measured, species, ambient temperature, etc. By extrapolation, it can be shown that a SAR of only 0.2-0.4 W/kg is required to promote a thermoregulatory response in a mammal with a body mass of 70 kg (e.g. weight of adult human). The specific absorption rate bioeffects data collected from laboratory mammals can be related by means of a simple power formula: threshold SAR (W/kg) = aMb, where M is body mass in kg, a is a constant and b is equal to approximately -0.5. Through this equation we have illustrated that a threshold SAR measured in a species weighing 100 g would be 10 times greater than that of a species weighing 10 000 g. Accordingly, a relatively low SAR that is physiologically ineffective in small mammals may be stressful to larger species.

Animals↗
PubMed1983

Passive joint position sense after total hip replacement surgery.

Passive joint position sense was tested in 10 subjects after unilateral total hip replacement surgery (which included capsulectomy). Varied initial limb position, amplitude, and velocity of movement were used. The unoperated side was used as a control. Statistically barely significant errors (p less than 0.025) on the operated side were detected at 0.6 degrees per second but not at 2 degrees per second. No significant differences were noted among the different hip positions. The results indicate that the ability to detect passive hip joint position sense remains largely, but not completely, intact after hip joint replacement. The joint capsule, ligaments, and joint surfaces, although not essential for kinesthesia, may provide some limb movement and position information, the absence of which is not now clinically apparent.

Follow-Up Studies↗
PubMed1978

Hemifacial spasm and the facial nucleus.

Spontaneous and associated hyperkinetic facial movements and contracture which follow injury to the seventh cranial nerve (postparalytic hemifacial spasm) or arise without known previous injury (cryptogenic hemifacial spasm) are pathological motor phenomena not found in the distribution of other cranial or somatic motor nerves. The commonly expressed hypotheses of pathogenesis--aberrant regeneration and fiber excitation by false synapse formation (ephapses) at the site of injury--cannot account for all aspects of these phenomena or for the uniqueness of such movements to the distribution of the seventh nerve. The suggestion is made that the existing diversity of facial motor behavior, which encompasses voluntary, emotional, and especially automatic, associated, and reflexive movements, is based on a unique central organization that sets it apart from other motor groups. I hypothesize that because of this organization, the changes following axonal injury--which include selective deafferentation, glial response, axonal sprouting, functional reconnection, and hyperexcitability from dendritic spike generation--can unmask and augment automatic, associated, and reflexive movements already present in the facial neuronal network to result in facial hyperkinesia.

Animals↗
PubMed1977

Effect of photoperiod and cold acclimation upon plasma free fatty acid levels in the white rat.

1. Animals were acclimated at 3 +/- 1 degrees C and at room temperature (22 degrees C) for 3 weeks. 2. At each acclimation temperature animals were maintained under either an 8:16 L:D cycle or a 16:8 L:D cycle. 3. Blood samples were taken before and after exposure to -38 degrees C for 30 min. 4. Free fatty acid levels were greatest in cold acclimated animals which were maintained on a short light cycle. 5. Interaction between acclimation and photoperiod was apparent.

Acclimatization↗
PubMed1977

A different form of "pure agraphia": syntactic writing errors in a patients with motor speech and movement disorders.

Three patients are described who displayed syntactic writing errors in combination with a motor speech disturbance and impaired motor limb function. Two of the patients had bulbar amyotrophic lateral sclerosis (ALS). Agraphia appeared when verbal communication was no longer possible. Autopsy in one patient disclosed only lesions consistent with ALS. The third patient had palilalia and chorea and although not aphasic, his written language showed persistent syntactic errors. We hypothesize that the agraphia in these patients occurred because of the combination of disordered feedback from the motor speech apparatus and limbs.

Adult↗