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Safety and feasibility of dobutamine-atropine stress echocardiography for the diagnosis of coronary artery disease in diabetic patients unable to perform an exercise stress test.

OBJECTIVE: Dobutamine stress testing is increasingly used for the diagnosis and functional evaluation of coronary artery disease. However, little is known about the safety and feasibility of this stress modality in diabetic patients. RESEARCH DESIGN AND METHODS: We studied the impact of diabetes on hemodynamic profile and on the safety and feasibility of dobutamine (up to 40 microg x kg(-1) x min(-1)) and atropine (up to 1 mg) stress echocardiography for the diagnosis of coronary artery disease in 1,446 consecutive patients (aged 60+/-12 years, 962 men) with limited exercise capacity and suspected myocardial ischemia. Of these, 184 patients were known to have IDDM or NIDDM. The test was considered feasible when 85% of the maximal heart rate and/or an ischemic end point (new or worsened wall motion abnormalities, ST segment depression, or angina) was achieved. RESULTS: No myocardial infarction or death occurred during the test. There was no significant difference between diabetic and nondiabetic patients with regard to heart rate increase during dobutamine stress echocardiography (58+/-25 vs. 61+/-24 beats/min), peak rate pressure product (18,400+/-3,135 vs. 18,048+/-4454), or the prevalence of hypotension (systolic blood pressure drop of >40 mmHg) (7 vs. 5%), ventricular tachycardia (5.4 vs. 4.5%), and supraventricular tachycardia (3 vs. 4%) during the test. Dobutamine stress echocardiography was feasible in 92% of the diabetic patients and in 90% of the nondiabetic patients. Coronary angiography was performed in 55 diabetic and 240 nondiabetic patients. Sensitivity, specificity, and accuracy of dobutamine stress echocardiography for the diagnosis of coronary artery disease in diabetic patients were 81, 85, and 82%. Those in nondiabetic patients were 74, 87, and 77%, respectively (NS). CONCLUSIONS: Dobutamine stress echocardiography is a feasible method for the diagnosis of coronary artery disease in patients with limited exercise capacity with a comparable safety, feasibility, and accuracy in diabetic and nondiabetic patients.

Aged↗

The Effect of Stress on Spontaneous Nest Leaving Behavior in the Mouse: An Improved Model of Stress-Induced Behavioral Pathology.

The present experiments were conducted to develop a more sensitive and reliable model of stress-induced behavioral pathology in the mouse. Male mice were housed singly in nest cages connected to either a circular tunnel, a recreational cage or a large box with food foraging apparatus. Spontaneous nocturnal out of nest activity or food foraging behavior in these environments was continuously monitored for a two week period during which time the effects of stress were examined. It was found that both repeated restraint and aggression stress markedly and persistently reduced out of nest nocturnal activity or food foraging behavior in all 3 environments but did not alter activity in a novel open field or plus maze or food or saccharin intake in the nest cage. In a preliminary experiment the reduction in out of nest activity by stress was attenuated by prior chronic treatment with the antidepressant, desmethylimipramine. Plasma corticosterone was elevated immediately after aggression stress but reduced 5 hr after chronic aggression stress. The reduction in activity did not appear the result of increased anxiety as measured by spontaneous risk assessment behavior in the nest. It is concluded that the decrease in out of nest activity after stress in the present studies models a withdrawn behavioral state and may be due to either or both a decrease in appetitive motivation to leave the nest or an increased aversion to the external environment which does not apparently involve anxiety.

Journal Article↗

[Controversies in stress echocardiography: the indications, diagnostic accuracy and stratification of dobutamine stress echocardiography].

In recent years, stress echocardiography has become a valuable tool in the diagnosis, stratification and prognostic evaluation of coronary artery disease. Stress echocardiography has been performed with a variety of methods, including exercise, atrial pacing and pharmacological stress with the use of adenosine, dipyridamol and dobutamine. Either of these modalities of stress echo are a good choice in the evaluation of ischemic disease and the selection of one over another should depend on the patient's characteristics, experience of the stress echo laboratory and clinical needs (in the detection of viability there is greater experience in the use of dobutamine making this the most popular choice when evaluating myocardial hibernation). The aim of this paper is to review the indications, diagnostic accuracy and prognostic stratification of dobutamine stress echocardiography, comparing them with those obtained with other stress echo modalities and with nuclear techniques.

Cardiotonic Agents↗

[Expressions of JWA protein and heat stress protein 70 induced by cell differentiation inducers combined with heat stress in K562 cells].

OBJECTIVE: To study how the combined effects of various differentiation inducers and heat stress on the expression of JWA protein in K562 cell, the relationship between JWA and Hsp70 expression, and the signal regulation mechanism possibly involved. METHODS: The experimental model was established in K562 cells. Various directional differentiation inducers (TPA, Ara-C, hemin, adriamycin, ATRA and As(2)O(3)) were used alone or combined with heat shock treatment (42 degrees C, 2 h). Western blot was used for detecting expressions of JWA, Hsp70, heat stress factor 1 (HSF1) and HSF2. RESULTS: (1) The expressions of both JWA protein and Hsp70 were significantly up-regulated after K562 cells treated by TPA (100, 200 ng/ml) or adriamycin (4 x 10(-8) mol/L) 48 h, and followed by heat shock (42 degrees C, 2 h). However, the opposite effects were observed when the cells treated by hemin (3 x 10(-5) mol/L, 48 h), Ara-C (80 ng/ml, 48 h) and As(2)O(3) (1 x 10(-6) mol/L, 48 h) followed by 2 h heat shock. No obvious changes were found when the cells treated by ATRA (1 x 10(-6) mol/L, 48 h) alone or followed by heat shock. (2) Both the heat shock transcriptional factors HSF1 and HSF2 did not show any significant changes when K562 cells were treated with various differentiation inducers and followed by heat stress. CONCLUSION: JWA not only takes part in the regulation of K562 cellular differentiation, but also of heat stress, it might be the co-target gene of several differentiation inducers and heat stress. The expression of Hsp70 seems not mediated by both HSF1 and HSF2 in K562 cells undergoing directional differentiation or heat stress treatment. JWA is likely to be a new signal molecule similar to Hsp70 signal pathways. The results show that JWA takes part in the mechanism of K562 cell response to heat stress.

Blotting, Western↗

Increased peroxidation of erythrocytes of stress-susceptible pigs: an improved diagnostic test for porcine stress syndrome.

When incubated with solutions of hydrogen peroxide, erythrocytes of stress-susceptible pigs produced more by-products of lipid peroxidation (as measured as thiobarbituric acid-reactive substances [TBARS]) than did erythrocytes from stress-resistant pigs. Using this technique, discrimination between the 2 pig types was absolute at hydrogen peroxide concentrations of 0.9 and 1.5%. This was in contrast to other methods of identifying stress-susceptible pigs, such as osmotically induced erythrocyte lysis and the determination of plasma pyruvate kinase and creatine kinase activities, for which considerable overlap of data was observed between pig types. The increased TBARS production by erythrocytes was further evidence for the existence of an antioxidant abnormality in stress-susceptible pigs. However, because there were no discernible differences in the major blood antioxidant-related values between stress-susceptible and stress-resistant pigs, the nature of the defect remains unclear. The production of TBARS by erythrocytes when incubated with hydrogen peroxide provides an improved method for identifying stress-susceptible pigs.

Animals↗

[Induced imagination as a methodologic paradigm in assessing stress perception and stress processing].

The methodological paradigm of the induced imagination has been tested as an alternative diagnostic access to stress and coping. Assumptions on the therapeutic applications of imagery techniques (i.e. Cautela, 1967; Lang, 1978; Leuner, 1980; Wolpe, 1958) have been integrated with cognitive concepts of visual imagery (Kosslyn, 1980; Kosslyn, Brunn, Cave & Wallach, 1984; Paivio, 1971; Steiner, 1980) to deduce a theoretical framework of emotional imagery. An emotionally involving imagery scene is generated when semantic-, spatial- and motoric-relational representations of an imagined scene are constructed and actions are to be performed by the subject. The electrodermal activity (EDA) serves as a physiological indicator of stress. Ten subjects have been tested. The main results are: 1. Stressful imaginations correlate with significantly higher physiological activity than relaxation phases and imagery scenes with agreable content. 2. Different sequences of a stressful imagination can be differentiated psychophysiologically: Parts of imagery appraisals and emotions show higher physiological activity than sequences which consist of descriptions of situational and environmental elements. 3. It could be shown that not the verbalisation itself but different contents of imagery scenes correlate with different physiological activities. These results provide strong support for the hypothesis that verbalisations of stressful events and coping strategies are related to increased physiological activity. The psychophysiological differentiation of stress processes implies the applicability of the induced imagination as a validity criterion for a criterion oriented questionnaire of stress and coping (Reicherts & Perrez, 1986).

Adaptation, Psychological↗

Diminished contractile reserve in patients with left ventricular hypertrophy and increased end-systolic stress during Dobutamine stress echocardiography.

Left ventricular hypertrophy (LVH) is associated with decreased contractile response to inotropic stimulation in animal models, but this has not been documented in humans. To determine whether LVH is associated with decreased myocardial contractile reserve, we measured left ventricular mass, heart rate-corrected velocity of circumferential fiber shortening (Vcfc), end-systolic stress, and LV ejection fraction (LVEF) in patients with LVH and increased end-systolic stress (n = 6) and in patients without LVH (n = 7) who had a normal response to dobutamine stress echocardiography (increased LVEF and no wall motion abnormalities). The afterload-dependent indexes of left ventricular systolic performance were normal at baseline and showed significant increases at peak dobutamine dose (LVH group: Vcfc 0.91 +/- 0.11 to 1.76 +/- 0.59, p = 0.006; LVEF 49 +/- 5 to 65 +/- 6, p = 0.001; group without LVH: Vcfc 1.16 +/- 0.24 to 1.99 +/- 0.36, p = 0.001; LVEF 61 +/- 6 to 68 +/- 6, p = 0.05). The Vcfc/ end-systolic stress relation, a load-independent index of myocardial contractility, rose in a dose-dependent fashion in both groups, but the increment was significantly less for patients with LVH (p < 0.02), suggesting a blunted myocardial contractile reserve to inotropic stimulation. The change in heart rate-corrected velocity of circumferential fiber shortening per unit of change in end-systolic stress in each patient at each dobutamine dose showed a linear and inverse relationship. The increment in heart rate-corrected velocity of circumferential fiber shortening for a given reduction in end-systolic stress was larger in patients without LVH than in patients with LVH (p = 0.01). These results suggest that in patients with LVH and increased end-systolic stress, ventricular performance is maintained at the expense of limited myocardial contractile reserve, and that inotropic stimulation unmasks this abnormality, despite a normal response in LVEF and velocity of circumferential fiber shortening. This approach may identify patients with LVH at risk of developing systolic dysfunction and heart failure.

Adult↗

[Stress tests in old age. The choice of the stress protocol].

OBJECTIVE: To evaluate, in an elderly Portuguese population, the diagnostic capacities of the most popular treadmill stress test protocols. DESIGN: Retrospective study of an elderly Portuguese population submitted to a stress test. PATIENTS AND METHODS: A population of 45 patients (35 male), aged 65 or more years, consecutively submitted to a stress test. The average age of the group was 67.8 +/- 2.9 years. The three protocols (Bruce, Bruce Modified and Naughton) were comparatively studied in terms of the patients capacity to execute the protocol, capacity to obtain a maximum and a diagnostic stress test, and the complications of the stress test protocol. MAIN RESULTS: The Bruce protocol was used in 19 patients, the Bruce Modified in 13 patients and the Naughton protocol in 13 patients. The three protocols did not lead to any complication. The Bruce protocol led to a larger increment in heart rate (p < 0.001) and to larger maximum rate pressure product (p < 0.05) than the Naughton one. The Bruce protocol obtained a larger number of diagnostic tests (p < 0.01) and a significantly lower number of inconclusive stress tests. The Naughton protocol led to a larger duration of the exercise tests and was not suitable for some of the elderly patients owing to the exhaustion of the protocol. The results obtained with the Bruce Modified protocol were among those of other two protocols. CONCLUSIONS: In the elderly, the stress tests are safe and useful in the diagnosis of exercise induced ischemia and in the stratification of cardiovascular risk. From the protocols studied, the Bruce protocol was the most adequate, globally speaking, for this group of patients. The Bruce protocol presented a better diagnostic capacity with no complications related to the protocol.

Aged↗

A comparative photoelastic stress analysis of internal root stresses between RC Prep and saline when applied to the Profile/GT rotary instrumentation system.

The purpose of this study was to measure and compare the amount of stress produced by GT ProFile (GT) and ProFile (PF) rotary files lubricated with either RC Prep (RCP) or saline (S) on the walls of prepared simulated canals. Twenty-four 10-mm long canals with a 10 mm radius of curvature were prepared in PL-2 photoelastic acrylic blocks which were lubricated with either RCP or S. The files were inserted into a Nouvag handpiece mounted to an Instron 4502 universal testing machine and lowered into the canal at a rate of 60 mm/min and a rotational speed of 300 RPM. The following four GTs and four PFs were sequentially introduced into predetermined depths of each canal: 20/.10, 20/.08, 20/.06, 20/.04, 40/.04, 35/.04, 30/.04, and 25/.04. Total areas of stress created by each file were captured by digital video images and measured using Image J software. Statistical analysis of the data was performed using a two-way ANOVA (p < 0.05, n = 24). The GT/RCP group demonstrated a significant average of 64.22% less stress than GT/S group. The PF (25, 30, and 35)/RCP groups demonstrated a significant average of 27.02% less stress than the same S groups. PF (40) produced a negligible amount of stress regardless of the lubricant type. The results reveal that using RCP as a lubricant when instrumenting curved canals with GT and PF results in less stress when compared to saline.

Acrylic Resins↗

Cortisol response to a cognitive stress challenge in posttraumatic stress disorder (PTSD) related to childhood abuse.

Preclinical studies show that animals with a history of chronic stress exposure have increased hypothalamic-pituitary-adrenal (HPA) axis reactivity following reexposure to stress. Patients with posttraumatic stress disorder (PTSD) have been found to have normal or decreased function of the HPA axis, however no studies have looked at the HPA response to stress in PTSD. The purpose of this study was to assess cortisol responsivity to a stressful cognitive challenge in patients with PTSD related to childhood abuse. Salivary cortisol levels, as well as heart rate and blood pressure, were measured before and after a stressful cognitive challenge in patients with abuse-related PTSD (N=23) and healthy comparison subjects (N=18). PTSD patients had 61% higher group mean cortisol levels in the time period leading up to the cognitive challenge, and 46% higher cortisol levels during the time period of the cognitive challenge, compared to controls. Both PTSD patients and controls had a similar 66-68% increase in cortisol levels from their own baseline with the cognitive challenge. Following the cognitive challenge, cortisol levels fell in both groups and were similar in PTSD and control groups. PTSD patients appeared to have an increased cortisol response in anticipation of a cognitive challenge relative to controls. Although cortisol has been found to be low at baseline, there does not appear to be an impairment in cortisol response to stressors in PTSD.

Adolescent↗

The effect of chronic restraint stress on spatial learning and memory: relation to oxidant stress.

The aim of this study was to investigate the effect of chronic restraint stress (RS) on spatial learning and memory. Fifty healthy male Wistar rats, aged three months were used. They were equally divided into five groups--C: Control, W: Water Maze, CS-1: Restrained for 21 days (1 h/day) + water maze protocol following stress period, CS-2: Restrained for 28 days (1 h/day) + water maze protocol during last 7 days of stress period, CS-3: Restrained for 21 days and allowed to recovery for 7 days (1 h/day). Corticosterone levels were higher in all stress groups than in C and W groups. Nitrite levels of frontal cortex and hippocampus were found to be elevated in chronic stress groups with respect to C and W groups. Thiobarbituric acid reactive substances (TBARS) of both tissues were increased significantly in CS1 and CS2 groups compared with C, W, and CS3 groups. Escape latencies of CS1 and CS2 groups were longer than those of the W group on each day of acquisition. In transfer test, CS1 and CS2 groups stayed significantly shorter in target quadrant according to the W group. Significant correlations between corticosterone and either nitrite or TBARS of hippocampus and frontal cortex were found. Both acquisition and memory performances were negatively correlated with plasma corticosterone level, nitrite, and TBARS levels of hippocampus and frontal cortex. The results of this study suggest that stress-induced lipid peroxidation may affect the acquisition and memory performances.

Analysis of Variance↗

Stress-induced premature senescence or stress-induced senescence-like phenotype: one in vivo reality, two possible definitions?

No consensus exists so far on the definition of cellular senescence. The narrowest definition of senescence is irreversible growth arrest triggered by telomere shortening counting cell generations (definition 1). Other authors gave an enlarged functional definition encompassing any kind of irreversible arrest of proliferative cell types induced by damaging agents or cell cycle deregulations after overexpression of proto-oncogenes (definition 2). As stress increases, the proportion of cells in "stress-induced premature senescence-like phenotype" according to definition 1 or "stress-induced premature senescence," according to definition 2, should increase when a culture reaches growth arrest, and the proportion of cells that reached telomere-dependent replicative senescence due to the end-replication problem should decrease. Stress-induced premature senescence-like phenotype and telomere-dependent replicatively senescent cells share basic similarities such as irreversible growth arrest and resistance to apoptosis, which may appear through different pathways. Irreversible growth arrest after exposure to oxidative stress and generation of DNA damage could be as efficient in avoiding immortalisation as "telomere-dependent" replicative senescence. Probabilities are higher that the senescent cells (according to definition 2) appearing in vivo are in stress-induced premature senescence rather than in telomere-dependent replicative senescence. Examples are given suggesting these cells affect in vivo tissue (patho)physiology and aging.

Aging↗

Shear stress induces iNOS expression in cultured smooth muscle cells: role of oxidative stress.

After deendothelialization, the most luminal smooth muscle cells of the neointima are in contact with blood flow and express inducible nitric oxide synthase (iNOS) in vivo. We hypothesized that shear stress may be a stimulus for this iNOS overexpression. We have thus submitted smooth muscle cells to laminar shear and measured the iNOS expression. Shear stress (20 dyn/cm(2)) induced iNOS mRNA and protein expression, whereas brain NOS mRNA expression was decreased. Conversely, nitrite production was increased. This production was blocked by a selective iNOS inhibitor. Pyrrolidine dithiocarbamate, an antioxidant molecule, and BXT-51072, a gluthation peroxidase mimic, both inhibited the shear-induced iNOS expression. Shear stress also increased the expression of both membrane subunits of NADPH oxidase p22(phox) and Mox-1. Shear stress activated the redox-sensitive nuclear translocation of the transcription nuclear factor-kappaB (NF-kappaB) and stimulated the degradation of both cytosolic inhibitors kappaB alpha and beta. These results show that shear stress can induce iNOS expression and nitrite production in smooth muscle cells and suggest that this regulation is probably mediated by oxidative stress-induced NF-kappaB activation.

Animals↗

Peritraumatic dissociation, acute stress, and early posttraumatic stress disorder in victims of general crime.

OBJECTIVE: To compare the relation between peritraumatic dissociation and acute stress and the early development of posttraumatic stress disorder (PTSD) in victims of general crime. METHOD: A total of 48 subjects were assessed within 24 hours of the trauma, using the Peritraumatic Dissociative Experiences Questionnaire Self-Report Version (PDEQ-SRV). They were followed longitudinally to assess acute stress (2 weeks after the assault,) using the Standford Acute Stress Reaction Questionnaire (SASRQ), and posttraumatic stress (at 5 weeks), using the Clinician-Administered PTSD Scale (CAPS) and the Impact of Event Scale (IES). RESULTS: Among PTSD subjects mean PDEQ scores were significantly higher (mean 3, SD 0.9) than in those without PTSD (mean 2.3, SD 0.7) (t = 2.78, df 46, P = 0.007). Among PTSD subjects, mean SASRQ scores were significantly higher (mean 97.9, SD 29.2) than in those without PTSD (mean 54.8, SD 28.2) (t = 4.9, df 46, P = 0.00007). CONCLUSIONS: High levels of peritraumatic dissociation and acute stress following violent assault are risk factors for early PTSD. Identifying acute reexperiencing can help the clinician identify subjects at highest risk.

Acute Disease↗

Plant responses to abiotic stresses: heavy metal-induced oxidative stress and protection by mycorrhization.

The aim of this review is to assess the mode of action and role of antioxidants as protection from heavy metal stress in roots, mycorrhizal fungi and mycorrhizae. Based on their chemical and physical properties three different molecular mechanisms of heavy metal toxicity can be distinguished: (a) production of reactive oxygen species by autoxidation and Fenton reaction; this reaction is typical for transition metals such as iron or copper, (b) blocking of essential functional groups in biomolecules, this reaction has mainly been reported for non-redox-reactive heavy metals such as cadmium and mercury, (c) displacement of essential metal ions from biomolecules; the latter reaction occurs with different kinds of heavy metals. Transition metals cause oxidative injury in plant tissue, but a literature survey did not provide evidence that this stress could be alleviated by increased levels of antioxidative systems. The reason may be that transition metals initiate hydroxyl radical production, which can not be controlled by antioxidants. Exposure of plants to non-redox reactive metals also resulted in oxidative stress as indicated by lipid peroxidation, H(2)O(2) accumulation, and an oxidative burst. Cadmium and some other metals caused a transient depletion of GSH and an inhibition of antioxidative enzymes, especially of glutathione reductase. Assessment of antioxidative capacities by metabolic modelling suggested that the reported diminution of antioxidants was sufficient to cause H(2)O(2) accumulation. The depletion of GSH is apparently a critical step in cadmium sensitivity since plants with improved capacities for GSH synthesis displayed higher Cd tolerance. Available data suggest that cadmium, when not detoxified rapidly enough, may trigger, via the disturbance of the redox control of the cell, a sequence of reactions leading to growth inhibition, stimulation of secondary metabolism, lignification, and finally cell death. This view is in contrast to the idea that cadmium results in unspecific necrosis. Plants in certain mycorrhizal associations are less sensitive to cadmium stress than non-mycorrhizal plants. Data about antioxidative systems in mycorrhizal fungi in pure culture and in symbiosis are scarce. The present results indicate that mycorrhization stimulated the phenolic defence system in the Paxillus-Pinus mycorrhizal symbiosis. Cadmium-induced changes in mycorrhizal roots were absent or smaller than those in non-mycorrhizal roots. These observations suggest that although changes in rhizospheric conditions were perceived by the root part of the symbiosis, the typical Cd-induced stress responses of phenolics were buffered. It is not known whether mycorrhization protected roots from Cd-induced injury by preventing access of cadmium to sensitive extra- or intracellular sites, or by excreted or intrinsic metal-chelators, or by other defence systems. It is possible that mycorrhizal fungi provide protection via GSH since higher concentrations of this thiol were found in pure cultures of the fungi than in bare roots. The development of stress-tolerant plant-mycorrhizal associations may be a promising new strategy for phytoremediation and soil amelioration measures.

Antioxidants↗

Displaced adolescents in Croatia: sources of stress and posttraumatic stress reaction.

This study explored sources of stress and psychosocial reactions of adolescents displaced as a result of the war in the Republic of Croatia. The most frequent stressful events they faced were loss of home (80%), loss of personal belongings (66.7%), separation from family members (66.7%), damage to property (48.9%), exposure to enemy attacks (46.7%), and death of a family member or friend (37.8%). Among the most frequent posttraumatic stress reactions were intrusive images (48.9%), loss of interest (40.9%), restlessness (37.8%), appetite disturbances (33.3%), and increased irritability (31.1%). The exposure to a greater number of stressful events was related to increased depression. More posttraumatic stress reactions were evident in females, in adolescents who were exiled for longer periods, and in those whose parents were more anxious. Adolescents who manifested a higher number of stress reactions had poorer expectations regarding their future.

Adolescent↗

Pressure transmission ratio reproducibility in stress continent and stress incontinent women.

Our objective was to determine the effect of cough strength on pressure transmission ratios and establish quantitative and qualitative intra-observer test-retest reproducibility of pressure transmission ratios calculated from dynamic urethral pressure profilometry. The study included 242 consecutive urodynamic evaluations on women without pelvic organ prolapse. Dynamic urethral pressure profiles were performed in duplicate with coughs of different intensities. The analysis included pressure transmission ratios from the proximal 3 urethral quartiles (Q1 through Q3) and the mean pressure transmission ratio calculated from these quartiles. The final diagnoses were stratified into genuine stress incontinence, 135 (56%), and stress continence, 107 (44%). Correlations were strong for pressure transmission ratios from the first versus the second dynamic urethral pressure profile (K = 0.712 for mean). While the variation in cough intensity between hard and soft coughs averaged 30 cm H2O (P < 0.001), correlation's were equally strong between hard and soft cough pressure transmission ratios (K = 0.712 for mean). When mean pressure transmission ratios were stratified into below 90% and at least 90% categories, 83.5% of subjects had test-retest concordance (K = 0.671). Concordance rates were less for stress continent subjects (80.0%; K = 0.527) than for genuine stress incontinence subjects (86.4%; K = 0.679). Pressure transmission ratios appear to have reasonable quantitative and qualitative reproducibility which is unaffected by cough strength. The degree of individual variability limits the utility of pressure transmission ratios to diagnose genuine stress incontinence independent of other, equally variable clinical and urodynamic parameters, but this measure is sufficiently reproducible to be useful in characterizing stress sphincteric function in population studies.

Aged↗

The influence of stress and stress hormones on the transplantability of a non-immunogenic syngeneic murine tumor.

Quantitative transplantation assays of a syngeneic murine adenocarcinoma have been used to investigate the effects of stress hormones and tumor take probability. Cortisol, injected intraperitoneally one hour before and 3 hours after tumor cells, caused a dose dependent reduction of TD50 (number of tumor cells required for 50% takes) by factors of from 4 at a total dose 4 microng/g to 68 at 400 microng/g. ACTH, given at 0.2 I.U. daily for 9 days spanning the time of tumor cell injection, reduced the TD50 2.5-fold, indicating that the peak gluco-corticoid level achieved, rather than its duration, was of greater significance. Adrenaline, while much less effective than cortisol, produced an 8-fold reduction in TD50 at its maximum tolerable dose. The effect of cortisol simulated that of whole body irradiation (WBI), and while both these agents depress immune reactivity, evidence is presented to suggest that immunological mechanisms are not responsible for their effect. WBI constitutes a systemic stress, and the demonstration that surgical trauma (laparotomy) could also reduce the TD50 for this tumor suggested that both might act via endogenous glucocorticoids. However, the failure of prior total adrenalectomy of mice to abrogate the effect of either WBI or laparotomy indicated that stress hormones were not essential intermediaries. It is concluded that both stress hormones, especially glucocorticoids, and stressful procedures acting independently of stress hormones, can facilitate tumor transplantation.

Adrenal Glands↗