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Biomedical subjects

W Winters

Publications and source records attributed to W Winters.

12 recordsLinked to original sources
PubMed2001

Hyperventilation beyond fight/flight: respiratory responses during emotional imagery.

Hyperventilation (HV) is often considered part of a defense response, implying an unpleasant emotion (negative valence) combined with a strong action tendency (high arousal). In this study, we investigated the importance of arousal and valence as triggers for HV responses. Forty women imagined eight different scripts varying along the arousal and valence dimensions. The scripts depicted relaxation, fear, depressive, action, and desire situations. After each trial, the imagery was rated for valence, arousal, and vividness. FetCO2, inspiratory and expiratory time, tidal volume, and pulse rate were measured in a nonintrusive way. FetCO2 drops and decreases in inspiratory and expiratory time occurred in all but the depressive and the relaxation scripts, suggesting that a defense conceptualization of hyperventilation is not always appropriate.

Adolescent↗
PubMed2001

Acquiring symptoms in response to odors: a learning perspective on multiple chemical sensitivity.

In this chapter, a learning account is discussed as a potential explanation for the symptoms in multiple chemical sensitivity. Clinical evidence is scarce and anecdotal. A laboratory model provides more convincing results. After a few breathing trials containing CO2-enriched air as an unconditioned stimulus in a compound with harmless odor substances as conditioned stimuli, subjective symptoms are elicited and respiratory behavior is altered by the odors only. Also, mental images can become conditioned stimuli to trigger subjective symptoms. The learning effects cannot be explained by a response bias or by conditioned arousal, and they appear to involve basic associative processes that do not overlap with aware cognition of the relationship between the odors and the CO2 inhalation. Learned symptoms generalize to new odors and they can be eliminated in a Pavlovian extinction procedure. In accordance with clinical findings, neurotic subjects and psychiatric cases are more vulnerable to learning subjective symptoms in response to odors. Consistent with a learning account, cognitive-behavioral treatment techniques appear to produce beneficial results in clinical cases. Several criticisms and unresolved questions regarding the potential role of learning mechanisms are discussed.

Administration, Inhalation↗
PubMed2001

Critical conditions for hyperventilation responses. The role of autonomic response propositions during emotional imagery.

Hyperventilation is often conceived of as part of a fight-or-flight response, triggered by situations with high arousal and negative valence. However, a previous study using emotional imagery found hyperventilation responses during imagery of high-arousal scenes regardless of their valence. Those imagery scripts contained suggestions of autonomic activity, which may have partly induced or enhanced the hyperventilatory responsivity. The present study used four emotional scripts--depicting relaxing, fearful, depressive, and pleasant situations--without suggestions of autonomic or respiratory responses. After each imagery trial, participants rated their imagery for valence, arousal, and vividness. Fractional end-tidal carbon dioxide (FetCO2), inspiratory and expiratory time, tidal volume, and pulse rate were measured in a non-intrusive way. Results showed significant FetCO2 drops during the fearful and pleasant scripts. However, this effect was much smaller compared to imagery scripts with autonomic response propositions. Participants imagining scripts without autonomic response information found it harder to imagine the scripts vividly and reported lower levels of subjective arousal.

Adolescent↗
PubMed1999

Discordant radiograph interpretation between emergency physicians and radiologists in a pediatric emergency department.

OBJECTIVES: To describe the types of discrepancies in radiograph interpretation between emergency physicians and radiologists in a pediatric emergency department, and to determine the impact of discrepant interpretations on patient care. METHODS: Prospective cohort study of discordant radiographs from the period beginning March 1, 1995 and ending March 31, 1996. During this period, 2083 radiographs were coded by the radiologist as concordant or discordant. Three hundred forty-nine were coded as discordant, and 324 were eligible for the study. Charts were reviewed for relevant physical examination findings and emergency department management. Discrepancies that affected patient care were deemed clinically significant. RESULTS: Twenty-three (1.1%) of 2083 radiographs were interpreted differently by the emergency physician and the radiologist in a way that might have changed patient management. This represents 7% (23/324) of the radiographs originally coded by a radiologist as discrepant. The most common discrepancy was a patient with a normal chest examination and a radiograph interpreted as having an infiltrate by the emergency physician, but subsequently read as having no infiltrate by a radiologist (12/324). These patients may have received antibiotics unnecessarily. Two discrepant interpretations had the potential to have serious consequences to the patient if not identified. One patient with cardiomegaly and another patient with free air on abdominal radiograph were not noted by the emergency physician. CONCLUSIONS: Emergency physicians would benefit from more rigorous interpretation of chest x-rays to avoid unnecessary treatment with antibiotics. Emergency physicians do a good job interpreting plain radiographs, but occasionally miss significant findings that could lead to adverse outcomes. The presence of radiologists to immediately read radiographs 24 hours a day could prevent missed findings, but, given the small number of significant misinterpretations, is unlikely to be cost effective.

Bone and Bones↗
PubMed1995

Establishing clinically relevant standards for tachypnea in febrile children younger than 2 years.

OBJECTIVE: To determine values for defining tachypnea in febrile children younger than 2 years that best identify those at risk for pneumonia. DESIGN: Prospective case series. STUDY PATIENTS: Children younger than 2 years presenting to the emergency department of a children's hospital with a temperature of 38 degrees C or higher. INTERVENTIONS: Using a standardized method, respiratory rates were obtained on eligible children for 1 year. Study patients were classified as having pneumonia or no pneumonia based on clinical evaluation and chest radiograph findings. Receiver operating characteristic curves were constructed to select the values for respiratory rate that maximized sensitivity and specificity of tachypnea as a sign of pneumonia. RESULTS: Data were analyzed for 572 children; pneumonia was present in 42 (7%). The diagnostic utility of tachypnea was maximal when cutoff values for respiratory rates of 59/min in infants younger than 6 months, 52/min in those aged 6 through 11 months, and 42/min in those aged 1 to 2 years were selected. Based on these definitions, tachypnea as a sign of pneumonia had a sensitivity of 73.8%, specificity of 76.8%, positive predictive value of 20.1%, and negative predictive value of 97.4%. CONCLUSIONS: Tachypnea, as defined in this study, is an important predictive sign of pneumonia in febrile children younger than 2 years. Conversely, the absence of tachypnea obviates the need for chest radiography in most settings.

Fever↗
PubMed1985

Commentary on 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD).

There is deep concern about the long term health effects of exposure to phenoxy herbicides and the contaminant TCDD; however, there is considerable scientific and medical uncertainty regarding the health effects from exposure to these chemicals. There are at least ten ongoing studies on reproduction, morbidity and mortality as well as studies of tissue concentrations of TCDD that are attempting to determine the health effects of these chemicals (see Table 2). Appropriate efforts should be made to prevent human and environmental exposure and to decontaminate the environment while awaiting the results of these investigations. Animal toxicity studies show such wide variations that extrapolations from a different species to humans are tenuous. Human studies on exposed workers and nonoccupational exposures are difficult to interpret because the exposure has not been quantified and because workers were exposed to mixtures of chemicals. Chloracne appears to be an important specific clinical marker of TCDD exposure, however, it can be caused by structurally similar compounds. Many of the past studies on human health effects of 2,4,5-T and TCDD are controversial. Since the scientific data are not firm, no specific statements can be made regarding the long term health effects at this time. Any individual who has had a significant exposure to TCDD should see his/her physician and have appropriate consultation. Long term follow up will be required. Physicians should be instructed regarding the possible manifestations of TCDD exposure to look for chloracne, soft tissue masses, muscle pain, fatigue, peripheral neuropathy, tender hepatic enlargement, enlargement, elevated liver enzymes, elevated lipids, prolonged prothrombin time, hemorrhagic cystitis and hirsutism.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Generalization of acquired somatic symptoms in response to odors: a pavlovian perspective on multiple chemical sensitivity.

OBJECTIVE: Somatic symptoms that occur in response to odors can be acquired in a pavlovian conditioning paradigm. The present study investigated 1) whether learned symptoms can generalize to new odors, 2) whether the generalization gradient is linked to the affective or irritant quality of the new odors, and 3) whether the delay between acquisition and testing modulates generalization. METHODS: Conditional odor stimuli (CS) were (diluted) ammonia and niaouli. One odor was mixed with 7.4% CO2-enriched air (unconditional stimulus) during 2-minute breathing trials (CS+ trial), and the other odor was presented with air (CS- trial). Three CS+ and three CS- trials were conducted in a semirandomized order (acquisition phase). The test phase involved one CS+-only (CS+ without CO2) and one CS- test trial, followed by three trials using new odors (butyric acid, acetic acid, and citric aroma). Half of the subjects (N = 28) were tested immediately, and the other half were tested after 1 week. Ventilatory responses were measured during and somatic symptoms were measured after each trial. RESULTS: Participants had more symptoms in response to CS+-only exposures, but only when ammonia was used as the CS+. Also, generalization occurred: More symptoms were reported in response to butyric and acetic acid than to citric aroma and only in participants who had been conditioned. Both the selective conditioning and the generalization effect were mediated by negative affectivity of the participants. The delay between the acquisition and test phases had no effect. CONCLUSIONS: Symptoms that occur in response to odorous substances can be learned and generalize to new substances, especially in persons with high negative affectivity. The findings further support the plausibility of a pavlovian perspective of multiple chemical sensitivity.

Adolescent↗
PubMedDate not supplied

Expression of gene-specific RNA in cultured cells exposed to rotating 60-Hz magnetic fields.

Replicate sets of cultures of mouse and of human cells were exposed to cyclic, sine wave, 60-Hz rotating magnetic fields of 1.0 Gs (1 Gs [symbol: see text] 0.1 mT) for 24-, 48-, or 72-h periods. Total RNA extracted from unexposed control and from magnetic field exposed cells was dot blot hybridized to a number of oncogene probes (including v-myc, v-fos, v-raf, and v-Ha-ras), a probe for 3611 murine sarcoma virus, a probe for the 70,000 dalton heat shock protein (hsp70), and a probe for the long terminal repeat sequence of mouse mammary tumor virus. Comparisons of levels of RNA in unexposed and magnetic field exposed cells measured by densitometer readings of resulting autoradiographs revealed no significant increases or decreases in RNA levels in magnetic field exposed cells with the seven probes tested.

Animals↗