Role of the trochlear nerve in eye abduction and frontal vision of the red-eared slider turtle (Trachemys scripta elegans).

Horizontal head rotation evokes significant responses from trochlear motoneurons of turtle that suggests they have a functional role in abduction of the eyes like that in frontal-eyed mammals. The finding is unexpected given that the turtle is generally considered lateral-eyed and assumed to have eye movements instead like that of lateral-eyed mammals, in which innervation of the superior oblique muscle by the trochlear nerve (nIV) produces intorsion, elevation, and adduction (not abduction). Using an isolated turtle head preparation with the brain removed, glass suction electrodes were used to stimulate nIV with trains of current pulses. Eyes were monitored via an infrared camera with the head placed in a gimble to quantify eye rotations and their directions. Stimulations of nIV evoked intorsion, elevation, and abduction. Dissection of the superior oblique muscle identified lines of action and a location of insertion on the eye, which supported kinematics evoked by nIV stimulation. Eye positions in alert behaving turtles with their head extended were compared with that when their heads were retracted in the carapace. When the head was retracted, there was a reduction in interpupillary distance and an increase in binocular overlap. Occlusion of peripheral fields by the carapace forces the turtle to a more frontal-eyed state, perhaps the reason for the action of abduction by the superior oblique muscle. These findings support why trochlear motoneurons in turtle respond in the same way as abducens motoneurons to horizontal rotations, an unusual characteristic of vestibulo-ocular physiology in comparison with other mammalian lateral-eyed species.

Corticosteroids and the cardiovascular response to stress: a pilot study of the 35% CO2 challenge in Addison's disease.

OBJECTIVE: Glucocorticoids play an essential role in the neuroendocrine response to stress, influencing both the hypothalamic-pituitary-adrenal (HPA) axis and the sympatho-adrenomedullary (SAM) axis at several levels. In this pilot study, a clinical model of primary adrenocortical failure (Addison's disease, AD) has been used to evaluate the role of circulating glucocorticoids in both the autonomic and psychological response to stress. DESIGN AND SUBJECTS: Five subjects with known AD underwent a randomized, double-blind, placebo-controlled investigation in which they received fixed glucocorticoid plus mineralocorticoid hormone replacement or placebo for 48 h prior to a 35% CO2 challenge. MEASUREMENT: Psychological responses immediately before and after CO2 exposure were assessed by questionnaire. Systolic blood pressure (SBP) and heart rate were measured automatically at 1-min intervals for 5 min before and 5 min after the CO2 exposure. RESULTS: While on hormone replacement, all subjects had an identical response to CO2 to that recorded in normal volunteers (initial bradycardia, an increase in blood pressure and subjective feelings of anxiety). On no replacement, however, the bradycardia and anxiety responses were not significantly altered, but the pressor response was markedly attenuated (+15.6 +/- 5 mmHg on replacement compared with +4.2 +/- 3.3 mmHg off replacement; P = 0.043). CONCLUSIONS: These data provide further evidence that the CO2-induced bradycardia is a direct--presumably parasympathetic--response to CO2 independent of the pressor effect, and that the pressor response itself is dependent on the presence of the circulating corticosteroid.

A new test for autonomic cardiovascular and neuroendocrine responses in diabetes mellitus: evidence for early vagal dysfunction.

AIMS/HYPOTHESIS: Diabetic autonomic neuropathy affects many physiological systems, producing a variety of important clinical manifestations. It is associated with high morbidity and mortality, particularly during times of stress. This is thought to be due to an increased risk of cardiac arrhythmias, although the exact mechanisms involved have yet to be fully elucidated. The aim of the present study was to investigate the endocrine, cardiac autonomic and psychological responses of diabetic patients with and without autonomic neuropathy to a single breath of 35% CO(2). METHODS: The 35% CO(2) challenge was performed in 20 male diabetic subjects, 11 of whom had autonomic neuropathy. RESULTS: Baseline and stimulated cortisol, prolactin, systolic blood pressure and emotional arousal were similar in the two groups. However, subjects with autonomic neuropathy failed to demonstrate the expected CO(2)-induced bradycardia seen in the non-neuropathic patients (p<0.0001). CONCLUSIONS/INTERPRETATION: The CO(2) challenge can be safely and easily administered to produce hypothalamic-pituitary-adrenal axis and cardiac autonomic activation, as well as emotional arousal. The test clearly distinguishes between subjects with and without cardiac autonomic neuropathy and could be an important adjunct to the methods currently available for the investigation and diagnosis of diabetic autonomic neuropathy.

Contaminated medication precipitating hypoglycaemia.

We report a case of hypoglycaemia in a patient with diet-controlled type 2 diabetes. Enquiries and investigations led to a diagnosis of sulfonylurea poisoning from contaminated herbal medication.

Learning to care for dying patients: a controlled longitudinal study of a death education course.

BACKGROUND: This study examines the long-term impact of a medical-school death education course on death-related anxiety and attitudes. METHODS: A four-year longitudinal, controlled study design was used. Ninety-nine course participants and 92 controls were initially evaluated using the Collett-Lester Fear of Death Scale and a semantic differential technique measuring attitudes toward the dying patient and his or her family. The evaluation was repeated at the end of the course and yearly thereafter. RESULTS: Attitudes towards "treating the dying patient" and "dealing with the dying patient's family" were improved as a result of the course. The effects were sustained throughout medical school, with significant differences between the groups at the end of the course (p < 0.001) and for third-year students (p < or = 0.002). Regarding fear of death, analyses showed no significant group-time interaction at any test period (p > or = 0.13). CONCLUSIONS: Preclinical education has an enduring effect on attitudes involving end-of-life care.

A three-dimensional virtual environment for modeling mechanical cardiopulmonary interactions.

We have developed a real-time computer system for modeling mechanical physiological behavior in an interactive, 3-D virtual environment. Such an environment can be used to facilitate exploration of cardiopulmonary physiology, particularly in situations that are difficult to reproduce clinically. We integrate 3-D deformable body dynamics with new, formal models of (scalar) cardiorespiratory physiology, associating the scalar physiological variables and parameters with the corresponding 3-D anatomy. Our framework enables us to drive a high-dimensional system (the 3-D anatomical models) from one with fewer parameters (the scalar physiological models) because of the nature of the domain and our intended application. Our approach is amenable to modeling patient-specific circumstances in two ways. First, using CT scan data, we apply semi-automatic methods for extracting and reconstructing the anatomy to use in our simulations. Second, our scalar physiological models are defined in terms of clinically measurable, patient-specific parameters. This paper describes our approach, problems we have encountered and a sample of results showing normal breathing and acute effects of pneumothoraces.

Modeling mechanical cardiopulmonary interactions for virtual environments.

We have developed a computer system for modeling mechanical cardiopulmonary behavior in an interactive, 3D virtual environment. The system consists of a compact, scalar description of cardiopulmonary mechanics, with an emphasis on respiratory mechanics, that drives deformable 3D anatomy to simulate mechanical behaviors of and interactions between physiological systems. Such an environment can be used to facilitate exploration of cardiopulmonary physiology, particularly in situations that are difficult to reproduce clinically. We integrate 3D deformable body dynamics with new, formal models of (scalar) cardiorespiratory physiology, associating the scalar physiological variables and parameters with corresponding 3D anatomy. Our approach is amenable to modeling patient-specific circumstances in two ways. First, using CT scan data, we apply semi-automatic methods for extracting and reconstructing the anatomy to use in our simulations. Second, our scalar models are defined in terms of clinically-measurable, patient-specific parameters. This paper describes our approach and presents a sample of results showing normal breathing and acute effects of pneumothoraces.

Hypnosis as an aid for tinnitus patients.

This study was undertaken to evaluate hypnosis versus stress management as therapeutic modalities in the treatment of tinnitus. Participants were recruited from the local tinnitus association and the Otolaryngology Division of the Department of Surgery. The instruments were the following standardized tests (NIMH Diagnostic Int. Schedule; SCL 90R, Beck Depression Inventory) in addition to a tinnitus questionnaire. Improvement was shown on 5 separate scales, some alleviated by both types of treatment and others singularly by hypnosis or stress management. The data reinforce the use of behavioral techniques and suggest that different techniques may be more appropriate for specific symptoms.

Psychological distress in cancer patients and their spouses.

The degree of psychosocial distress experienced by 15 cancer patients with newly diagnosed metastatic disease and their spouses was investigated. Of interest were mean changes over the six-month interval following diagnosis, and correlations between partners at 0, 3, and 6-7 months. The Psychosocial Adjustment to Illness Scale (PAIS) and the Family Environment Scale (FES) were used to quantify adjustment. Several PAIS subscales exhibited increasing distress over time for patients: Social Environment (p = 0.004), Vocational Environment (p = 0.028), and Psychological Distress (p = 0.029). FES Conflict increased over time (p < 0.005), while Intellectual Cultural Orientation declined (p = 0.02), both for spouses only. Of 24 patient-spouse PAIS correlations (7 subscales plus a global scale, at three times), 7 (29%) were 0.70 or greater (ps < 0.01). Of 30 FES correlations, 17 (57%) were 0.7 or higher (ps < 0.01). These results suggest that some stresses increase over time, and that spouses and patients share a similar perceived level of distress. Health professionals must address the psychological distress of the spouse as well as the patient.

New staple fixation for an Austin bunionectomy.

There are several methods available for the internal fixation of the Austin bunionectomy. By carefully forming a Kirschner wire into the shape of a staple, fixation of the neck osteotomy is maintained. The method is simple, fast, and reliable, and it requires no additional instrumentation.

Will a course on death and dying lower students' death and dying anxiety?

This course describes a 7-week, one-and-one-half-hour per week course on Death and Dying and examines its impact on medical students' attitudes. The 30 participants were tested on attitudes about death and dying pre- and post-course. The pre- and post-course fears about death and dying were measured with the 32-item Collett-Lester Death Anxiety Scale, which measures fear of death and the dying process as these apply to self and others. The Semantic Differential technique was used to measure the pre- and post-course attitudes toward "treating the dying patient" and "dealing with the dying patient's family." There was a decrease in anxiety about death and dying when the posttest was compared with the pretest on the anxiety scales, with death of self and death of others reaching significance (p = .04 and .04). There was a decrease in anxiety scores on the Semantic Differential on treating the dying patient and dealing with the dying patient's family (p = less than .001 for both).

Hypnosis on a consultation-liaison service.

The use of hypnosis was demonstrated on a psychiatric consultation-liaison service (CLS) in a broad spectrum of medically hospitalized patients. Hypnosis was employed as an adjuvant measure to traditional medical and psychologic treatment modalities. Tapes for autohypnosis were used for reinforcement. Twenty-nine women and eight men from 24 to 75 years of age were hypnotized for relief of depression, pain, anxiety, or side-effects from chemotherapy. Results were excellent (total to almost total relief of symptoms) in 68% of the patients, fair in 22%, and poor in 11% with no differences among the results with the various conditions. This report demonstrates that hypnotherapy can be an extremely useful tool in the medical management of patients on a CLS.

Attitudes of elderly people about clinical research on aging.

This study determined the factors influencing participation of elderly people in research. It involved subjects who signed consent for a study and those who refused consent. Consenters had significantly more positive feelings about being used as a subject; giving urine; giving blood; having a physical examination; being interviewed; taking an IQ test; answering questions; being a subject to help others; finding out about problems and as a way to pass time; and telling an interviewer the truth. Reasons given for partaking in research were the personality of the interviewer, interest in the project, and benefits to subject or others.

The physician's role with the terminally ill patient.

The physician encounters many issues and problems when working with the terminally ill. It is important to remember that the most important aspect of care for the dying is to maintain open and honest communication among the doctor, the patient, and the family. In brief, the physician should play a major role in helping the dying patient. Open communication and support must be continually provided by the physician, both to the dying patient and to the family. All it takes, basically, is common sense and human compassion. No matter how often the physician treats dying patients, he or she should never be casual or matter-of-fact about death. Death should always command respect and awe, but it need never terrorize us or cause us to turn away from providing help to the dying patient. Those who care for the terminally ill may find, to their surprise, that great satisfaction can be derived from this work. One becomes enriched by observing the courage of many dying patients. Therein lies the challenge and the reward.

Conducting clinical research in geriatric populations.

Clinical research on geriatric populations requires adaptation of traditional methodologies, modification of expectations, and the development of new procedures. Some aspects of research methodology are unique to studies of geriatric populations. Experience in this relatively new area of geriatric research indicates that new partnerships between researchers and long-term care providers are needed. These new relationships require an understanding of the needs of geriatric populations and of the differences between providers of long-term care and of acute-care. Researchers must consider heterogeneity of the population, the probability of multiple diagnoses and treatments, subject attrition, and the possibility of invalid data. Such considerations require extra staff, more time, and increased funding as well as new thinking about study design and protocol implementation.