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Biomedical subjects

J Ernst

Publications and source records attributed to J Ernst.

At least 19 recordsLinked to original sources
PubMed1990

[X-ray and ultrasonic diagnosis of rheumatic-inflammatory diseases of the elbow].

The X-ray anatomy and ultrasound appearance of the normal elbow joint are described. The ultrasound testing procedure for visualizing the soft tissue layer and the intra-articular inflammatory substrate is presented. The general X-ray signs of arthritis in the elbow joint are presented, and then the radiological particularities and characteristics of the various forms of arthritis are discussed with reference to their different etiologies.

Arthritis, Gouty↗
PubMed1990

The effects of applicant's health status and qualifications on simulated hiring decisions.

The effects of having diabetes or obesity on simulated job decisions was evaluated in a two (qualifications, high v. marginal) by three (diabetes, mildly obese, or normal) design. Subjects were 295 adults, averaging 5.02 years of full-time employment in white-collar settings, recruited in advanced level graduate or undergraduate business classes. Each subject examined a job description and a resume of the 'applicant' and viewed a 5-minute videotape. The applicant's face was never seen and an off-camera voice, constant across all conditions, was dubbed in for the applicant's responses to the interviewer's questions. Subjects were then asked to rate the applicant's qualification level and demeanor during the interview and to recommend whether or not to hire the individual. Subjects were also asked to make ratings about the applicant's work habits, work reliability and absenteeism, and interpersonal skills (e.g. emotional problems, likeability). Results indicated that level of quantification affected decisions to hire the applicant in the predicted direction. However, the obese applicant was rated as less qualified for the job, and both the diabetic and obese applicant were less likely to be hired, although they were rated similarly on personal appearance, attitude during the interview, and communication skills. Additionally, both the obese and the diabetic applicant were viewed as having poorer work habits. The diabetic was rated as much more likely to have medically-related job absences, whereas the obese applicant was rated as more likely to have other absences (e.g. abusing company privileges by feigning illness) and to have emotional and interpersonal problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Local muscular strain dependent on the direction of horizontal arm movements.

Manual material handling still plays an important role in assembly work as well as in the service industry. By means of an ergonomic layout of working places, the effects of disadvantageous working conditions, especially static load resulting from unfavourable postures of the body as well as unnecessary physiological cost arising from body movements may be avoided. In this context knowledge about the optimum directions of horizontal arm movements is fundamental. Therefore by means of advanced methods of multi-channel electromyography (EMG) and applying computer assisted evaluation methods, physiological responses to one-handed horizontal material handling in a sitting position were recorded. In order to obtain myoelectric signals from the most important task-relevant muscles out of more than 40 muscle groups of the hand-arm-shoulder-system, preceding research was done also aiming at standardized lead positions for surface EMG. Groups of five young females each participated in a series of successive experiments, in which the direction of movements of the left arm was varied. The subjects worked without and with an external load imposed by weights of 0, 1, 2 and 4 kg. The movements between 20 degrees and 230 degrees--measured from the frontal plane of the subjects--included working from ahead and from behind. The lifting distance was 38 cm starting from different outward points within the reach to a fixed point near the body. Also in one test series the handling frequency was varied between 12, 24 and 48 lifts per minute. Assessment of the physiological cost by electromyographic activities (EA), especially the determination of the most stressful and least expensive directions of repetitive horizontal movements, was more effective when differentiating static and dynamic portions of muscular strain than common means of EA.

Adult↗
PubMed1989

The post-antibiotic effect defined by bacterial morphology.

Three strains of Escherichia coli were incubated with either ciprofloxacin or ampicillin. Filamentation of bacteria was observed after 1-2 h. After 5 h of contact with either drug the percentage of filaments exceeded 90%. The organisms were washed and incubated on drug free medium. Antibiotics when bound to an enzyme render that enzyme inactive; upon removal of the organisms from the antibiotic, the synthesis of enzymes resumes. The period of time encompassing the inactive enzymatic state of the organism at the time of removal from the drug to the time that enzymes restore complete function is our definition of the post-antibiotic effect (pae). Bacterial morphology reflects the variations in activity of these enzymes. The pae was determined by both the morphology of the organisms and the current growth kinetic method. The presence of 10% filaments and 90% bacilli was selected to indicate the endpoint of the pae by morphological criteria. The pae by morphology was 4 h for ciprofloxacin and 3 h for ampicillin. By the growth kinetics method it was 2 h for ciprofloxacin and zero for ampicillin.

Ampicillin↗
PubMed1989

Absorption of calcium and magnesium from fortified human milk by very low birth weight infants.

Absorption of calcium and magnesium endogenous to human milk, as well as calcium and magnesium added as an exogenous supplement to human milk, was determined in 9 very low birth wt infants. Human milk, intrinsically labeled with stable isotopic tracers of calcium and magnesium, was prepared by administering isotopic tracers intravenously to a lactating woman. Different isotopic tracers, which were representative of calcium and magnesium in the supplement (Enfamil Human Milk Fortifier, Mead Johnson Nutritional Div.), were added to the intrinsically labeled milk. The fortified milk, which was labeled with two calcium tracers and two magnesium tracers, was given orally to the test subjects in a single feeding. True absorption of calcium and magnesium was determined from differences between the doses of tracer ingested and the quantities of tracer excreted in the feces. Stable isotopic tracers were quantified by fast atom bombardment mass spectrometry. These results demonstrate that the fractional absorptions of calcium in the human milk and the added mineral supplement are 80 and 82%, respectively. A total of 89% magnesium endogenous to human milk and 86% of magnesium derived from the mineral supplement was absorbed by the VLBW infants.

Biological Availability↗
PubMed1989

Methods to evaluate the wellbeing of laboratory primates: comparisons of macaques and tamarins.

Three objective behavioral tests are described for the assessment of wellbeing and possible enrichment of laboratory primates. One test, foraging for food in a pickup tray, proved practical for both macaques and tamarins. It provides positive human interaction as well as standardized evaluation of appetite for food and sensory-motor coordination. A puzzle feeder provided more complex foraging which could be performed by macaques, but not by tamarins. A third noninvasive test, used only with macaques, measured daily energy expenditure and sleep-wakefulness cycles as expressed in the diurnal rhythm of homecage activity. Normative data indicate the usefulness of each. Further refinement and validation of new tests and enrichment strategies requires a major research effort. Definitive measures such as those described here, coupled with data on long-term health outcomes, are essential before regulations for primate care can be revised with confidence.

Animal Welfare↗
PubMed1988

Activity of amikacin and ampicillin in succession and in combination.

One strain each of Escherichia coli and Streptococcus faecalis were exposed to amikacin and ampicillin in combination as well as in succession. Exposure to ampicillin for 1 hr followed by amikacin for 3 or 4 hr had the greatest antibacterial activity when the antibiotics were applied in succession. The least effective exposures for both organisms were 1 hr to amikacin followed by 3 or 4 hr to ampicillin. Exposure to the antibiotics in combination each at 1 MIC had the overall greatest antibacterial activity. Simultaneous exposure to the antibiotic combination does not necessarily mean simultaneous activity of both ampicillin and amikacin on the E. coli. The cell wall autolytic activities produced by ampicillin are triggered within 10 min after physical contact with the bacteria. In contrast, amikacin requires at least 30 min after physical contact to manifest its activity on the ribosome. Although physical exposure to both antibiotics in the combination is simultaneous, the specific activity of each is in fact sequential, with ampicillin acting first. This explains the synergistic effect of the combination. It appears, therefore, that the synergistic or antagonistic affect of a drug combination is determined by the sequence and timing of the antibacterial manifestations of its components.

Amikacin↗
PubMed1987

Neuropsychological problem-solving skills in the elderly.

This article describes the performance of a representative sample of 110 participants aged from 65 to 75 years. Participants completed the Trail-Making Test, Tactual Performance Test, and Booklet Category Test. Results confirmed that previously established cutoff scores used to determine impairment are not appropriate for this age group. Significant sex differences were found for the Tactual Performance Test and Booklet Category Test. Mean scores presented in this article provide useful normative standards for the three aforementioned tasks when given to patients aged from 65 to 75 years.

Aged↗
PubMed1987

Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R.

Several studies have reported positive correlations between measures of intelligence (a quasi-subject variable) and level of performance on neuropsychological tests; few, however, have presented test results by IQ grouping, which could be useful for comparative purposes. The present study examined the relationships of WAIS and WAIS-R Full Scale IQ to performance on a neuropsychological battery consisting of the Halstead-Reitan Battery (HRB), the Wide Range Achievement Test (WRAT), and the Wechsler Memory Scale (WMS). Four mixed neuropsychiatric samples provided cross-cultural and within-laboratory replications, two tested with WAIS and two with WAIS-R. Means and standard deviations for each measure were presented by five IQ levels within each sample. IQ was strongly related to scores on problem-solving tasks, auditory and linguistic measures, memory tasks, academic achievement levels, and tactual imperceptions, while motor functioning and sensory suppressions were less strongly related to IQ. IQ level was related to educational level in all samples. Correlations of years of education with dependent variables in the two WAIS-R samples were strong and replicable for WRAT scores, verbal memory measures, linguistic errors on the Aphasia Screening Test, and finger-tapping speeds but not for other HRB measures. Finally, IQ-HRB relationships were compared to those reported for other populations.

Achievement↗
PubMed1987

Effects of antibiotics on bacterial structure and their pathogenicity.

Subinhibitory concentrations of beta-lactam antibiotics as well as some other antibacterial agents alter the ultrastructure of bacteria. The separation of replicated genomes of Gram positive cocci is inhibited, and results in clusters of as many as 30 organisms held together by thick cross walls. The separation of the replicated genomes of Gram negative bacilli is also inhibited and results in the formation filaments. These altered forms of bacteria usually exhibit lower pathogenicity than their respective normal counterparts such as; decreased adherence to epithelial cells, higher susceptibility to phagocytosis and decreased output of bacterial enzymes. Contrary to common belief, subinhibitory concentrations do not generate a significant increase in bacterial resistance to the respective drug.

Animals↗
PubMed1986

Nitrogen sources for parenteral nutrition in the newborn infant.

Protein requirements for the preterm and term infant have been determined by a variety of methods. The parenteral protein needs of the very low birth weight infant are around 3 gm/kg/day and of the term infant approximately 2.2 gm/kg/day for maintenance of normal growth. These values are averages and may need to be modified for individuals depending upon a variety of potentially complicating factors. In this regard, many neonatologists recommend the provision of a maximum of 2 to 2.5 gm/kg/day of protein to newborns under most clinical situations. Whereas excessive administration of protein may result in adverse consequences, the tolerance of young infants to infusion of amino acid solutions is not well defined. Based upon animal studies of fetal amino acid utilization, the preterm infant may be capable of appropriately modifying its supply of amino acids over a relatively broad concentration range. It would appear that the supply of individual amino acids is adequately met by a number of amino acid solutions. The newer preparations appear to be more ideally suited to the special needs of the very low birth weight.

Amino Acids↗
PubMed1985

Ultrastructure of staphylococci in respiratory infections treated with nafcillin.

A patient with a pleural effusion containing Staphylococcus aureus was treated with nafcillin. Another patient with bilateral upper lobe infiltrates which grew S. aureus from a catheter inserted through a fiberoptic bronchoscope into the lesion was also treated with nafcillin. Electron microscopy of organisms grown while the patients were receiving nafcillin showed staphylococci which were twice as large as normal and contained multiple cross-walls and normal peripheral cell walls. Such abnormal staphylococci result from exposure to subminimum inhibitory concentrations of beta-lactam antibiotics.

Adult↗