Clinical ethics consultations: reasons for optimism, but problems exist

[The author identifies] five problems familiar to clinical ethicists. (1) Physicians often do not recognize important ethical issues. (2) Debate exists over whether such consultations should give specific management recommendations. (3) Principles of medical ethics cannot, by themselves, resolve real ethical issues. (4) The patient's interests sometimes conflict with the interests of the family, the health professionals, and the hospital. (5) Clinical ethics consultations take a toll on the consultant....[He] discuss[es] the implications of each problem for clinical ethics consultations and offer[s] a solution to it.     

Heart rate--QT relationships during baroreceptor stimulation with diminished autonomic influence on the ventricles. Ventricular autonomic tone and QT interval.

The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been accepted for many years as evidence that the action potential duration and hence QT are necessarily dependent on heart rate. Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this assumption, 26 conscious dogs divided into three groups were tested during baroreceptor stimulation by a bolus injection of phenylephrine. Seventeen dogs had been used in earlier studies in which they had undergone an experimental anterior myocardial infarction with apparent full recovery. A group of those dogs underwent beta-adrenergic blockade by intravenous atenolol 30 min prior to the baroreceptor activation. To test the intactness of the baroreceptor responses in the previously infarcted dogs, a third group of nine dogs that had had no prior myocardial infarction was included. All dogs were adapted to the laboratory environment and were not sedated during experiments. Simultaneous recordings of RR, QT interval, and phasic arterial pressure were made in all dogs before and during baroreceptor stimulation. In the normal group, and the previously infarcted group that received no atenolol, baroreceptor stimulation elicited a small (8/msec), but significant prolongation of the QT associated with a nearly 50% reduction in heart rate. The QT interval of the atenolol-treated dogs, although significantly more prolonged before stimulation, remained unchanged during the reflex. The data indicate that withdrawal of ventricular sympathetic tone may prolong the QT interval, thereby confirming the role of sympathetic innervation in the control of QT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Predictors of myocardial infarction over a span of 30 years in Roseto, Pennsylvania.

Predictors of myocardial infarction with or without survival were sought in a 30-year study of Roseto, Pennsylvania, a nearly exclusively Italian community of approximately 1,600, compared to the immediately adjacent town of Bangor with a population of approximately 5,000. At the start of the study the death rate from myocardial infarction among men in Roseto was less than half that in Bangor despite an equal prevalence of the usual risk factors, mainly smoking and diet. The communities were followed prospectively for 30 years during a striking social change in Roseto toward less family and community cohesion and more commitment to individual goals and adherence to materialistic values. During this period the prevalence of and mortality from myocardial infarction increased sharply to equal the situation in Bangor. The predictive values of measurements made of Rosetans during individual examinations in 1962-63 were tested against the outcome in 1990. Those who experienced fatal myocardial infarction and those who had a well documented infarction and survived were matched with and compared to controls. Although subjects with cholesterol concentration above 200 were twice as likely to experience myocardial infarction as those with concentrations below 200, less than 20% of those whose cholesterol concentration was above 200 experienced any evidence of myocardial infarction over the nearly 30-year period. Moreover, there were no significant differences between the coronary patients, with or without survival, and their sex, age, and cholesterol matched controls; nor were smoking, evidence of hypertension, diabetes, or obesity predictive of significant differences between the two groups. These data lead to the inference that while those with the conventional risk factors are more likely to develop myocardial infarction than are those without the risk factors, an even larger proportion of the population may have the risk factors and not succumb to myocardial infarction over a period of nearly three decades.     

Applied behavior analysis and the movement to restructure schools: Compatibilities and opportunities for collaboration

The field of applied behavior analysis has devoted considerable effort to the problem of educating America's youth. In addition to developing a wide range of procedures to improve children's academic and classroom survival skills, behavioral researchers have discussed a wide range of technological characteristics that are likely to facilitate the adoption of their procedures by educational decision-makers and practitioners. A movement to restructure American schools has become highly popularized within educational, political, and public media forums over the past several years. One general characteristic of this movement is its failure to recommend the more frequent implementation of applied behavior analysis techniques to educate America's youth. A close inspection of three global models for school reform, however, reveals notable compatibilities with the focus and goals of applied behavior analysis. Applied behavior analysts can collaborate with and contribute to the school restructuring movement by pursuing the more formal and systematic analyses of characteristics essential to the adoption process.     

Marital satisfaction and family stress as predictors of classroom behaviors

The purpose of this research was to examine the relationship between parents' perceptions of marital satisfaction and family stress and their third grade children's classroom behavior. Twenty-one married couples completed questionnaires during home visits. Behavior observations were made from videotapes of children recorded in their classroom during lunch and group academic periods on each of three days. Frequencies of peer interactions, solitary behaviors, and teacher interactions were coded. Regression analyses showed that mothers' level of marital satisfaction (but not fathers') predicted their children's frequency of peer interactions during lunch. Fathers' level of perceived family stress (but not mothers') predicted their children's frequency of peer interactions during lunch. Neither measure for either parent was related to the frequency of peer interactions, solitary behaviors, or teacher interactions observed during the academic sessions. These findings highlight the importance of assessing the potential differential relation of parent variables to children's trans-situational behaviors, and the examination of these variables in relation to different social-environmental contexts in which children participate outside the home.     

Data generation and analysis using spreadsheets

Modern spreadsheets are powerful and useful tools that can often replace special-purpose programs for generating data and for student analysis of simple statistical problems. The inherent flexibility of spreadsheets makes them especially convenient and extensible. Several templates for generating and analyzing data fort tests and analysis of variance are discussed. Users can specify then, \(\bar X\) , andSD of two or more groups and then execute macros that generate appropriate data. Overwriting the generated data with “real” values turns the spreadsheet into a data analysis program. Spreadsheets hold promise as valuable instructional supplements for simple designs, but they are less suitable for more complex designs, where special-purpose programs may be more appropriate.     

The Y chromosome, social signals, and offense in mice

Offense is one type of aggression in mice (Mus musculus/Mus domesticus). Offense was measured in a panel of testers design for two congenic strains of mice. The two congenic strains were DBA1Bg and DBA1. C57BL10-YBg. These differ in the Y chromosome. Offense was measured for the following dyadic pairs: Group 1 (DBA1 tested against a DBA1 opponent); Group 2 (DBA1 tested against a DBA1.C57BL10-Y opponent); Group 3 (DBA1.C57BL10-Y tested against a DBA1.C57BL10-Y opponent); and Group 4 (DBA1.C57BL10-Y tested against a DBA1 opponent). Group 1 was more aggressive than Group 3, whereas Group 2 was no more aggressive than Group 4. Thus, when the experimental and opponent pairs have the same Y chromosome, the congenics differ in offense, whereas when the experimental and opponent pairs have different Y chromosomes, the congenics do not differ in offense. These findings are consistent with the hypothesis that these Y chromosomes affect the display of and response to social or other stimuli for offense of mice. These stimuli may be individual recognition chemosignals in urine.     

Synaptic plasticity in the hypoglossal nucleus of female canaries: structural correlates of season, hemisphere, and testosterone treatment

The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization.