Biomedical subjects

J Fertig

Publications and source records attributed to J Fertig.

6 recordsLinked to original sources

PubMed1989

The effects of d-amphetamine on arousal, cognition, and mood after prolonged total sleep deprivation.

Thirty-six normal male subjects underwent total sleep deprivation for 48 hours, were then administered either placebo, 5, 10, or 20 mg of d-amphetamine, and sleep deprived for an additional 12 hours. Sleep deprivation produced a significant reduction in sleep latency, as well as marked decrements in cognitive performance and self-ratings reflecting vigor and fatigue. Amphetamine reversed these effects in a dose-related way but the pattern and persistence of the reversal varied across measures. After 20 mg, sleep latency normalized for several hours, but then declined. Behavioral effects tended to follow the pattern of sleep latency. On cognitive tasks, 20 mg produced a sustained return to normal performance in an attentional arithmetic task and a gradual improvement in a verbal reasoning task. The partial temporal dissociation among sleep latency, behavioral, and cognitive effects suggests that varying doses of amphetamine may have time-related differential neurochemical effects or that various dimensions of arousal and alertness may be differentially sensitive to amphetamine.

Adult↗

PubMed1989

Impact of dental conditions on patients' quality of life.

Quality of life measures have rarely been used in dentistry to assess oral health status. The purpose of this paper is to assess the utility of using standard indicators to measure the impacts of dental conditions on patients' quality of life. Quality of life was conceptualized as a multidimensional construct including three major aspects: social functioning, measured by the Sickness Impact Profile; well-being, measured by the Gill Well-Being Scale, Spielberger State/Trait Anxiety Scale, and the Corah Dental Anxiety Scale; and symptoms, measured by the Kiyak Oral Functioning Scale, the McGill Pain Questionnaire, and the West Haven Multidimensional Pain Inventory. 152 patients were recruited from private dental practices consisting of 48 TMJ, 33 periodontal, 23 denture, and 48 recall patients. Patients in the first three groups reported numerous impacts on quality of life and the impacts were particularly severe for the TMJ patients. The indicators used were sensitive to differences among the four groups and hold promise for further development of quality of life indicators for use in epidemiologic surveys and clinical dental trials.

Activities of Daily Living↗

PubMed1984

The effects of smoking on ACTH and cortisol secretion.

The relationship among changes in plasma nicotine, ACTH, and cortisol secretion after smoking were investigated. Ten male subjects smoked cigarettes containing 2.87 mg nicotine and 0.48 mg nicotine. No rises in cortisol or ACTH were detected after smoking 0.48 mg nicotine cigarettes. Cortisol rises were significant in 11 of 15 instances after smoking 2.87 mg nicotine cigarettes, but ACTH rose significantly in only 5 of the 11 instances where cortisol increased. Each ACTH rise occurred in a subject who reported nausea and was observed to be pale, sweaty, and tachycardic. Peak plasma nicotine concentrations were not significantly different in sessions when cortisol rose with or without ACTH increases, but cortisol increases were significantly greater in nauseated than in non-nauseated smokers. Our data suggest that smoking-induced nausea stimulates cortisol release by stimulating ACTH secretion and that cortisol secretion in non-nauseated smokers may occur through a non-ACTH mechanism. It is not clear whether nicotine or some other stimulus inherent in smoking is responsible for cortisol secretion without ACTH secretion.

Adrenocorticotropic Hormone↗

PubMed1983

Reactivity to alcohol cues in alcoholics and non-alcoholics: implications for a stimulus control analysis of drinking.

The present study is an attempt to identify responses to alcohol-related stimuli which might differentiate alcoholics from non-alcoholics. The assumption was that alcoholics would be more reactive to alcohol cues because of prior conditioning history with respect to alcohol and drinking. Eight alcoholics in treatment were compared with ten non-alcoholic controls and two recovering alcoholics, using swallowing and salivation as the principal dependent measures. (The concordance of swallowing and salivation was validated using dental rolls with an independent group of ten alcoholics.) Five-minute "sniff-trials" were provided in which subjects smelled either cedar chips or their favorite alcoholic beverage, in a labelled container. Swallowing (salivation) and craving (desire to drink alcohol) were significantly elevated in alcohol-sniffing trials for alcoholics in treatment compared with non-alcoholics; cardiac rate and galvanic skin response duration were also elevated in alcoholics in treatment, though not significantly. Recovering alcoholics resembled alcoholics in treatment more closely than they resembled non-alcoholics. The data were examined in the context of conditioned withdrawal resembled non-alcoholics. The data were examined in the context of conditioned withdrawal and homeostatic protective mechanisms. Implications for the stimulus control analysis of drinking were discussed.

Adult↗

PubMed1977

A reflection on partial coherence in electron microscopy.

The concept of partial coherence, which originated in light optics, is investigated in the case of dark-field electron microscopy. Two atoms arbitrarily arranged in the object space are considered as sources of the secondary waves. The influence of lens aberrations is taken into account. The real degree of coherence gamma r is calculated for the STEM as well as the CTEM. In the case of atomic resolution, the finite size of the atoms significantly influences the degree of coherence, so that it becomes a function of the image coordinate. Analytical expressions are obtained for gamma r which are valid at present-day resolutions for both the CTEM and STEM. The dark-field intensity distribution in the detector plane of a STEM is calculated for an object consisting of two atoms in different configurations and for different positions of the scanning spot.

Microscopy, Electron↗

PubMed1976

Influence of detector geometry on image properties of the STEM for thick objects.

Plural electron scattering within thick objects broadens and smoothes the intensity distribution in the detector plane of a scanning transmission electron microscope. Detector arrangements have been determined which give maximum contrast and optimum S/N when the object details are large compared to the scanning spot. Asymptotic expressions for the optimum detector angles, specimen resolution, and S/N were obtained which are valid for objects thicker than approximately four elastic mean free path lengths. Exact calculations of the changes in contrast and S/N with thickness fluctuations in amorphous carbon foils were performed for atbitrary foil thicknesses. Elastic and inelastic electron scattering was taken into account.

Carbon↗