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Biomedical subjects

D Anderson

Publications and source records attributed to D Anderson.

At least 595 records · Page 33Linked to original sources
PubMed1980

The relationship between length of hospital stay and rapid-readmission rates.

The average length of stay for patients on the psychiatric service of a large VA hospital in California was nine days in mid-1977. Such brief hospitalizations often led to insufficient discharge planning and rapid readmissions, within one month of discharge. VA policy changed in July 1977, and longer lengths of hospital stay were initiated. The experiences with brief and longer-term hospitalization enabled the authors to study the rapid-readmission rates for each length of stay. Their data showed that an increase in length of stay from nine to 26 days was associated with a 55 per cent reduction in the rate of rapid readmission. They admit that it is too early to conclude that the longer patient stay was responsible for the decrease, and feel that additional longitudinal study is necessary.

California↗
PubMed1980

Voluntary heart-rate changes mediated by muscle tension and respiration.

20 undergraduates completed heart-rate mediation treatments (isometric exercise, relaxation, hyperventilation, and hypoventilation) with and without feedback. Heart rate increased during tension, decreased with relaxation, and changed even more with feedback. During hyperventilation the heart rates were lower than during hypoventilation, and this difference was even greater during trials with feedback. This paradoxical finding was attributed to the shallowness of the breathing. Additional data from an experiment on voluntary heart-rate control (n = 31) without feedback and one with biofeedback of heart rate (n = 18) showed that subjects were following heart-rate increase and decrease instructions with altered respiration rates. These observations are interpreted as indicating that biofeedback changes in heart rate are mediated by skeletal muscle tension, respiration, and other mediating mechanisms.

Biofeedback, Psychology↗
PubMed1980

Virus associated papillomas in colobus monkeys (Colobus guereza).

Numerous papillomas ranging in size from 1--10 mm were seen in four colobus monkeys (Colobus guereza). The lesions were confined to the fingers and toes and to the dorsal-lateral aspects of the hands and feet distal to the carpus and tarsus. Electron microscopy of two of the lesions revealed compactly arranged crystalline arrays of intranuclear virus particles in the epidermis. The particles were seen only in cells of the stratum granulosum and stratum corneum. By the negative stain technique, the non-enveloped spherical particles measured 52--58 mm in diameter. The arrangement of the capsomeres was consistent with an icosahedral symmetry. The observations suggested a viral etiology for the cutaneous papillomas similar to that of other mammalian species.

Animals↗
PubMed1980

Cardiovascular and sympathetic reactions to in-flight emergency responses among base fire fighters.

The responses of 12 healthy male fire fighters to simulated and actual in-flight emergencies were investigated. Subjects were aroused from sleep during all emergency responses. The ECG, blood pressure, heart rate (HR), rate-pressure product (RPP), and plasma norepinephrine (NE) responses were determined. Despite a mean HR increase of 112% (75 beats/min) and a 145% rise in RPP, there was no significant elevation in plasma NE concentration during the emergency response. Legible ECG tracings showed no abnormal ST segment deviations or arrhythmias. The HR, BP, and RPP results indicated a greater cardiovascular response to emergencies among inactive fire fighters than among those who were physically active. Based on the observed differences between emergency and simulated emergency responses, we concluded that the physiological reactions during emergency responses were due primarily to the arousal response. When suddenly aroused from sleep, the fire fighter's response to in-flight emergencies produces significant elevations in HR and myocardial oxygen consumption which were unrelated to increases in sympathetic activity.

Adult↗
PubMed1979

Field dependence and extraversion neuroticism on an inpatient psychiatric service.

Compared relationship between field dependence (FD) and the scales of Neuroticism (N) and Extraversion (E) using paraprofessionals (N = 22), professionals (N = 42) and psychiatric inpatients (N = 35) to elucidate the high FD found among the psychiatric inpatients. Recent evidence contradicts Witkins' (1965) early view that as a group, psychiatric inpatients would show psychopathology at the extremes of the FD continuum. The N scale was chosen because it taps a narrow behavior band, the individual's vulnerability to break down under stress. The major hypothesis that FD and N would be functionally related was based on previous empirical findings (Cattell, 1955) and Seligman's (1975) theory of "learned helplessness." Similarly, it was expected that age and sex (i.e., being female) were related functionally to FD. The latter hypotheses were supported. The hypothesis that the profiles of inpatients, professionals and paraprofessionals would throw more light on the high FD found among inpatients was not supported. The relationship between FD and N was discussed in terms of Seligman's (1975) concept of learned helplessness.

Adult↗
PubMed1979

Ovine placental vascular responses to indomethacin.

The administration of 10 mg/kg indomethacin to chronically catheterized near-term sheep resulted in a change in cotyledonary vascular resistance from 0.133 +/- 0.016 to 0.180 +/- 0.022 (mmHg . min)/ml (P less than 0.001). The noncotyledonary uterine vascular resistance increased to 191% of the original value (P less than 0.001) and the renal vascular resistance increased to 147% of the control value (P less than 0.001). The maternal blood pressure increased from 96 +/- 3.4 to 108 +/- 3.4 mmHg (P less than 0.001). Indomethacin (12 mg/kg) was given to nine fetuses, and observations were made in the control condition and at 15, 120, and 240 min. Cotyledonary vascular resistances were 144%, 152%, and 213% of the control values at those times. All changes were significant (P less than 0.03). The umbilical vascular resistance rose slowly throughout the study even though the concentration of indomethacin was falling during that time. These data suggest that this response may be an indirect effect. In the maternal circulation the rapid increase in the cotyledonary vascular resistance seen after indomethacin was probably due to a decreased level of endogenous prostaglandin synthesis.

Animals↗
PubMed1979

Biofeedback and relaxation effects in electromyographic biofeedback training: a methodological note.

The present study documented progressive reductions of electromyographic potentials in a biofeedback study involving instructions to 11 female and 5 male college students to both increase and decrease the feedback (and therefore the muscle tension). When only pre-experimental baselines were employed, electromyographic reductions were found with instructions to decrease the feedback. When repeated, nontreatment baseline conditions were employed as references for analysis, no electromyographic reductions were detected beyond the progressive reductions that occurred during those baselines.

Biofeedback, Psychology↗
PubMed1979

Metastasis-induced acute pancreatitis in small cell bronchogenic carcinoma.

Despite frequent metastatic involvement of the pancreas at postmortem examination in patients with small cell lung cancer, clinically observed pancreatitis due to metastatic pancreatic tumor rarely has been reported. This communication describes three cases of clinical acute pancreatitis occurring in a consecutive series of 40 patients with oat cell lung cancer. This complication may appear either as the initial manifestation of the neoplasm or during a recrudescent phase of the malignant growth. The diagnosis should be suspected in the presence of the clinical, laboratory, and radiologic features of acute pancreatitis in patients with known small cell carcinoma of the lung, especially if there is evidence of progression of the neoplastic disease elsewhere and no response to conservative medical management. Aggressive treatment with polychemotherapy can produce rapid clinical improvement and useful prolongation of survival.

Acute Disease↗
PubMed1978

Chromosomal analyses in vinyl chloride-exposed workers.

Chromosomal morphology from cultured peripheral lymphocytes was studied in 81 men; 57 of the men were employed on plants manufacturing vinyl chloride or polyvinylchloride, 19 were on-site controls and 5 were off-site controls. There was a significant increase in chromosomal abnormalities in the exposed workers when compared with the controls. The greatest statistically significant increase in total B and total C cells occurred in autoclave operators, with smaller increases in other job categories. The increase in chromosomal aberrations was correlated with the length of exposure and with a history during the year prior to sampling (1973--1974) of exposure to excursion levels of vinyl chloride. Information on smoking habits was obtained 18 months after blood sampling and a positive correlation between these and total C cell abnormalities was found. There was no positive correlation with various other parameters (bilirubin, platelets, gamma-glutamyltranspeptidase, alkaline phosphatase, alanine transaminase and aspartate transaminase). It was not possible to estimate which of the three parameters (smoking history, length of employment or exposure to excursion levels) was the most important.

Chromosomes↗
PubMed1978

An evaluation of 6 short-term tests for detecting organic chemical carcinogens.

A number of tests have been described which are thought to be capable of identifying carcinogens without using the actual induction of cancer as an endpoint. This study compared the performance of 6 such tests on a selection of 120 organic chemicals. The tests studies were: (1) mutation of Salmonella typhimurium; (2) cell transformation; (3) degranulation of endoplasmic reticulum; (4) sebaceous gland suppression; (5) tetrazolium reduction and (6) subcutaneous implant. A further 4 tests were examined briefly, but were not included in the complete evaluation. The chemicals were classified into carcinogens (58) and non-carcinogens (62) on the basis of published experimental data, and into 1 of 4 broad chemical classes. There was considerable variation between tests in their ability to predict carcinogenicity, with the cell-transformation test and the bacterial-mutation test being the most accurate (94% and 93% accurate respectively). These 2 tests were considered to be of general use in screening, since they were clearly more accurate than the others. Statistical consideration of various combinations of these tests showed that the use of cell transformation and bacterial mutation together, provide an advantage over the use of either test alone. The inclusion of the other 4 tests in a screening battery predictably resulted in a great increase in overall inaccuracy and loss of discrimination, even though the detection of carcinogens is improved. All the tests were shown to generate both false positive and false negative results, a situation which may be controlled by the use, where possible, of appropriate chemical-class controls, to identify the test which is optimal for the class of chemical under test. Structural analogy may have a part to play in the rapid detection of environmental carcinogens, and some general guidelines for its use are given.

Animals↗