The cardiovascular effects of beta adrenergic agonist drugs administered by nebulization.
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Bronchodilator Agents↗
Biomedical subjects
J A Hall
Publications and source records attributed to J A Hall.
In vivo demonstration of cardiac beta 2-adrenoreceptor sensitization by beta 1-antagonist treatment.
Treatment with beta 1-selective antagonists causes selective sensitization of isolated strips of human atrial myocardium to the inotropic action of epinephrine and beta 2-agonists but not of norepinephrine. To determine whether beta 1-selective antagonist treatment alters the responsiveness of cardiac beta 2-adrenoreceptors in vivo, we measured the positive chronotropic responses to salbutamol injected into the right coronary artery. Ten patients treated with atenolol (50-100 mg daily) were compared with 10 patients not treated with beta-blockers. The mean dose required to cause an increase in heart rate of 30 beats/min was 2.29 micrograms (log dose 0.36 +/- 0.12 micrograms [mean +/- SEM]) in the atenolol-treated patients. In the non-beta-blocker-treated patients, the dose required to cause an increase in heart rate of 30 beats/min was significantly greater, 8.91 micrograms (log dose 0.95 +/- 0.11 micrograms) (p less than 0.005). We conclude that treatment with beta 1-selective beta-blockers leads to increased cardiac responsiveness to beta 2-adrenoreceptor stimulation. This may be the underlying mechanism of the beta-blocker withdrawal syndrome and may make the heart more susceptible to the adverse effects of epinephrine in situations of stress (e.g., myocardial infarction).
Adrenergic beta-Antagonists↗
Consultative geriatric assessment for ambulatory patients. A randomized trial in a health maintenance organization.
Previous studies have shown that comprehensive geriatric assessment and follow-up can improve the health of hospitalized elderly patients. To evaluate the effectiveness of consultative geriatric assessment and limited follow-up for ambulatory patients, we randomized 600 elderly patients who were enrolled in a health maintenance organization into three groups: (1) consultation by a geriatric assessment team, (2) consultation by a "second opinion" internist, and (3) only traditional health maintenance organization services (control patients). The geriatric assessment team identified previously unrecognized problems in 35% of patients and advised changes in medication regimens for more than 40%. Nevertheless, patients who received assessment achieved only a small benefit in cognitive function after 3 months, which was not sustained for 1 year. There was no difference among groups in other measures of health status. Consultative geriatric assessment with limited follow-up did not benefit most older ambulatory patients in a health maintenance organization; if such care can be used effectively for ambulatory patients, it will require either additional targeting or continuing care or both.
Aged↗
Characterization of the hamster DDT-1 cell aFGF/HGBF-I gene and cDNA and its modulation by steroids.
Syrian hamster DDT-1 cells are derived from smooth muscle of the ductus deferens. DDT-1 cell growth is increased by the addition of testosterone (T). Acidic fibroblast growth factor (aFGF) or basic fibroblast growth factor (bFGF) also known as heparin binding growth factor I and II (HBGF-I and HBGF-II) can replace T in the stimulation of growth in these cells. This phenomenon is correlated with testosterone's ability to elevate aFGF/HBGF-I mRNA. The increase steady-state levels of aFGF/HBGF-I mRNA were documented by northern blots and by in situ hybridization. Using a 520 bp human aFGF/HBGF-I cDNA probe, a genomic clone with a 38 kb DNA insert was isolated from a cosmid library. By restriction enzyme analysis and southern hybridization, it was determined that there are three coding exons. DNA sequence analysis showed all of the coding region and 3' noncoding sequences were on this clone. A 5' noncoding exon not in the 38 kb insert is indicated, based on the cDNA sequences and genomic sequences of aFGF/HBGF-I's from hamster DDT-1 cells and several other species. The cDNA for hamster aFGF/HBGF-I was isolated from a DDT-1 lambda gt11 library and sequenced. Comparison of the coding region of aFGF/HBGF-I from four species shows a greater than 90% conservation of amino acid sequence.
Amino Acid Sequence↗
Surgical management of breast disease in an obstetrics and gynecology group.
The surgical management of breast disease from 1978 through 1988 by the Women's Health Center of Logansport is reviewed. Three hundred twelve biopsy procedures resulted in the diagnosis of 59 cancers. Biopsy and mastectomy procedures were performed by the authors (obstetrician-gynecologists). There were no significant complications and all patients had an adequate surgical result. Preoperative needle localization techniques proved to be a safe and effective method to identify and remove nonpalpable mammographic abnormalities. Because women depend on their gynecologist for advice regarding reproductive organs including the breasts, it is logical for the gynecologic surgeon to become involved in the surgical management of breast disease.
Adult↗
Cocaine-induced stroke: first Jamaican case.
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Adult↗
Patient sociodemographic characteristics as predictors of satisfaction with medical care: a meta-analysis.
A meta-analysis was performed to examine the relation of patients' sociodemographic characteristics to their satisfaction with medical care. The sociodemographic characteristics were age, ethnicity, sex, socioeconomic status (three indices), marital status, and family size. Greater satisfaction was significantly associated with greater age and less education, and marginally significantly associated with being married and having higher social status (scored as a composite variable emphasizing occupational status). The average magnitudes of relations were very small, with age being the strongest correlate of satisfaction (mean r = 0.13). No overall relationship was found for ethnicity, sex, income, or family size. For all sociodemographic variables, the distribution of correlations was significantly heterogeneous, and statistical contrasts revealed the operation of several moderating variables. The meaning of the overall results and their relation to earlier reviews is discussed.
Age Factors↗
Older patients' health status and satisfaction with medical care in an HMO population.
Few studies have examined the relationship between older patients' satisfaction with medical care and their health status, and none of these investigations has been based at an HMO. To examine this question, data on 532 patients older than 70 years in an HMO were analyzed. Patients' reports of satisfaction with medical care were examined in relation to several dimensions of health status (based on self-reports, chart data, and physicians' ratings), their own sociodemographic characteristics, and characteristics of their primary physicians. Greater satisfaction was significantly associated with better self-rated health and physical function, less emotional distress, and more social activity but was not related to physicians' health ratings, number of diagnoses, or cognitive function. Mean levels of satisfaction were also significantly different for patients of different physicians but not appreciably related to patients' sociodemographic characteristics. When patient sociodemographic characteristics were controlled for, the relations of health status variables to satisfaction were essentially unchanged. It was concluded that the key issues to be resolved are whether better health leads to greater satisfaction or vice versa, and, in either case, whether the relations are mediated by factors relating to the patient's experience of medical care.
Aged↗
Performance quality, gender, and professional role. A study of physicians and nonphysicians in 16 ambulatory care practices.
The quality of medical care has rarely been evaluated in relation to practitioner or patient gender. Moreover, comparisons between physicians and nonphysicians typically are confounded by practitioner gender. In this study gender and professional role effects were analyzed separately for 162 male and female staff physicians, 191 male and female residents, and 73 female nonphysicians delivering adult and pediatric primary care in 16 ambulatory care practices. Analyses addressed influences of patient and practitioner gender as well as differences between physicians and nonphysicians. Results showed that female staff physicians performed better than male staff physicians for cancer screening in women by breast examination and Pap smears, but that female residents performed worse than male residents for urinary tract infections in children. Patient gender effects occurred for two tasks; for these, superior care was rendered to the gender with higher prevalence for the condition (girls for urinary tract infections, boys for otitis media). The results are considered in the context of the gender-relevance of particular medical tasks or conditions. Comparisons between physicians and nonphysicians were limited to female practitioners. Comparable or superior performance for nonphysicians was found for all tasks but one (cancer screening in women).
Ambulatory Care↗
Balloon dilatation of tricuspid stenosis caused by carcinoid heart disease.
Double balloon dilatation of tricuspid stenosis caused by carcinoid heart disease was successful in a woman of 77.
Aged↗
Enoximone potentiates the positive inotropic effects of beta-1- and beta-2-adrenoceptor stimulation in human atrial myocardium.
The aim of these studies was to determine whether phosphodiesterase inhibition by enoximone is able to regulate differentially beta 1- and beta 2-adrenoceptor (AR)-mediated inotropic effects. Strips of human right atrial myocardium were stimulated with noradrenaline plus ICI 118,551 (selective beta 1-AR stimulation) or adrenaline plus CGP 20,712A (selective beta 2-AR stimulation). Concentration-effect curves were determined in the absence or presence of enoximone. Enoximone alone was shown to produce dose-related positive inotropic effects. In tissues from beta 1-blocker-treated patients, enoximone potentiated the responses to both beta 1-AR and beta 2-AR stimulation. There was a fall in -log EC50 (mol/l) of 0.7 +/- 0.2 (mean +/- SEM; n = 6) for beta 1-AR stimulation and of 0.6 +/- 0.1 (n = 10) for beta 2-AR stimulation. The potentiation of beta 2-AR responses in non-beta-blocker-treated patients was similar with a fall in -log EC50 (mol/l) of 0.5 +/- 0.1 (n = 6). The extent of potentiation was not significantly different between beta 1-AR and beta 2-AR stimulation, nor between beta 1-blocker-treated patients and non-beta-blocker-treated patients. Further experiments showed that the potentiation by enoximone of the effects of catecholamines was unaltered by diazoxide (n = 6). Enoximone thus causes positive inotropic effects and potentiates the effects of catecholamines acting through both beta 1- and beta 2-AR. These actions are consistent with inhibition of cyclic AMP hydrolysis. The potentiation of the effects of catecholamines by phosphodiesterase inhibition appears unaltered by prior patient therapy with beta 1 blockers.
Adrenergic beta-Antagonists↗
Selective beta 1-adrenoceptor blockade enhances positive inotropic responses to endogenous catecholamines mediated through beta 2-adrenoceptors in human atrial myocardium.
We determined the relative contribution of beta 1- and beta 2-adrenoceptor stimulation to the positive inotropic responses of human atrial myocardium to catecholamines. (-)Norepinephrine produced stimulation predominantly through beta 1-receptors and (-)epinephrine through both beta 1- and beta 2-receptors. However, there were marked differences in the responses of tissues from patients treated with the beta 1-selective antagonist atenolol compared with non-beta-blocker-treated patients; surprisingly, beta 2-mediated responses were enhanced, and beta 1-mediated responses were unaltered. There was an enhanced responsiveness to (-)epinephrine (atenolol treated: -log M EC50, 7.57 +/- 0.07; non-beta-blocker treated: -log M EC50, 6.77 +/- 0.17; p less than 0.001), and the relative importance of beta 2-adrenoceptor stimulation was increased for both (-)norepinephrine and (-)epinephrine. In tissues from atenolol-treated patients, salbutamol, a beta 2-selective partial agonist, had an enhanced potency and a greater intrinsic activity (atenolol treated: -log M EC50, 7.13 +/- 0.09; intrinsic activity, 0.86 +/- 0.04; non-beta-blocker treated: -log M EC50, 5.76 +/- 0.44; intrinsic activity, 0.39 +/- 0.13). We investigated possible mechanisms underlying the enhanced responsiveness to beta 2 stimulation. Determination of beta 2-adrenoceptor affinity for salbutamol showed no change of affinity in atenolol-treated patients. Responses of the tissues to the cyclic AMP analogue dibutyryl cyclic AMP were not different between atenolol-treated and non-beta-blocker-treated patients. The results suggest that chronic blockade of beta 1-adrenoceptors causes enhanced coupling of beta 2-adrenoceptors to adenylate cyclase or to other mechanisms leading to increased contractile force.
Adrenergic beta-Antagonists↗
Administration of pig relaxin to beef heifers 4 or 7 days pre partum.
Crossbred beef heifers (N = 36) were assigned to one of three treatment groups: untreated controls (C; N = 15); Group R4, treated with pig relaxin (1.0 mg i.m.) 4 days pre partum (N = 11); or Group R7, treated with pig relaxin (1.0 mg i.m.) 7 days pre partum (N = 10). Bioactivity of the pig relaxin (UMC-R-P8) was determined by the mouse interpubic ligament assay to be greater than or equal to 3000 U/mg, both before and after the experiment was conducted. Peripheral serum immunoreactive relaxin values were 7.5, 3.4, 2.5, and 1.5 ng/ml at 2, 4, 6 and 8 h after injection of relaxin, respectively. Gestation lengths were 282.9 +/- 1.1, 285.5 +/- 1.3 and 285.6 +/- 1.5 days for Groups C, R4 and R7 (C vs R4 + R7; P congruent to 0.08). Calving difficulty score (1 to 4) tended to be greater (P congruent to 0.08) for Group R4 and R7 heifers (C vs R4 + R7; 1.3 +/- 0.24 vs 1.75 +/- 0.28 + 2.04 +/- 0.32), but the incidences of dystocia and retained placentae were not influenced by treatment (P greater than or equal to 0.10). The mean concentration and concentration profile of daily serum progesterone, oestradiol-17 beta, dihydroprostaglandin F-2 alpha and relaxin were not affected by treatment from 6 days pre partum through 2 days post partum. Cervical diameter, cervical softness score, pelvic measurements, and vulva opening length during the periparturient period were not affected (P greater than or equal to 0.10) by treatment, but all of these characteristics changed over time (P less than or equal to 0.01), relative to calving. We conclude that i.m. administration of pig relaxin (greater than or equal to 3000 U) does not effectively alter periparturient characteristics of beef heifers. Discrepancies between these results and those reported for intracervical administration cannot be readily explained.
Animals↗
A comparison of the effects of adrenaline and noradrenaline on human heart: the role of beta 1- and beta 2-adrenoceptors in the stimulation of adenylate cyclase and contractile force.
The stimulant effects of adrenaline and noradrenaline on contractile force and adenylate cyclase, mediated through beta 1 and beta 2-adrenoceptors, are analysed in isolated atrial and ventricular myocardium of man. The tissues were obtained from patients without advanced heart failure undergoing heart surgery. Usually, both adrenaline and noradrenaline stimulated adenylate cyclase predominantly through ventricular and atrial beta 2-adrenoceptors. Because the relative density of beta 2-adrenoceptors is usually smaller than that of beta 1-adrenoceptors, stimulation of one beta 2-adrenoceptor leads to the production of up to 10 times more cyclic AMP molecules than does stimulation of one beta 1-adrenoceptor. Adrenaline and noradrenaline maximally enhance contractile force through both atrial and ventricular beta 1-adrenoceptors. Adrenaline can also maximally enhance contractile force through atrial beta 2-adrenoceptors. In the ventricle, adrenaline increases force via beta 2-adrenoceptors by up to 60% of its maximal beta 1 response. Noradrenaline can increase atrial and ventricular contractile force through beta 2-adrenoceptors but only at high concentrations. Unexpectedly, in atria from patients treated with the beta 1-selective antagonist atenolol, contractile responses to adrenaline are markedly and selectively augmented through activation of beta 2-adrenoceptors. In atria from atenolol-treated patients equi-inotropic concentrations of adrenaline and noradrenaline acting through beta 2 and beta 1-adrenoceptors, respectively, cause similar increases of cyclic AMP and of cyclic AMP-dependent protein kinase activity.
Adenylyl Cyclases↗
Formation of ovarian follicular cysts and corpora lutea after treatment with antihistamine or indomethacin in prepubertal gilts.
Roles of histamine and prostaglandins in the induction of ovarian cysts after unilateral ovarian manipulation (MAN) and in the process of ovulation were evaluated in prepubertal gilts treated with pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Administration of pyrilamine maleate, an H1 receptor antagonist, before MAN or hCG injection reduced the number of cysts formed but did not alter ovulation rate. Administration of cimetidine, an H2 receptor antagonist, failed to alter the incidence, number, or diameters of cysts formed in response to MAN or the ovulation rate on non-MAN ovaries. Administration of indomethacin, an inhibitor of prostaglandin synthesis, before MAN or hCG injection did not alter the incidence, number, or diameters of cysts formed on MAN ovaries but reduced the number of corpora lutea on non-MAN ovaries. Excessive accumulation of fluid in ovarian cysts apparently was mediated by histamine interacting with the H1-type receptor. Enhanced secretion of prostaglandins produced by the cyclooxygenase pathway did not contribute to development of ovarian cysts but, unlike histamine, was required for formation of corpora lutea in prepubertal gilts treated with PMSG and hCG.
Aging↗
Autoradiographical localization of binding sites for porcine [125I]endothelin-1 in humans, pigs, and rats: functional relevance in humans.
Endothelin-1 (ET-1) is a recently discovered 21 amino acid peptide with potent vasoconstrictor properties. So far, its expression has been found only in porcine aorta, whereas its putative role as the endothelium-derived constricting factor (EDCF) would require it to be expressed and active in most vascular beds. We have used quantitative receptor autoradiography on pig, rat, and some human tissues to determine the distribution and localization of specific binding sites for ET-1. In some cases where binding sites were found, studies were performed to determine whether these are likely to be functional receptors. Binding sites for ET-1 have been found in heart (nerves greater than atria greater than ventricle greater than coronary arteries), kidney (glomeruli greater than papilla), adrenal (zona glomerulosa greater than medulla), cerebellum, spinal cord, gut, spleen, and lung. The binding of [125I]ET-1 was displaced at all these sites by unlabeled ET-1 but not by nitrendipine, apamin, and other vasoconstrictor peptides. ET-1 contracted strips of human coronary artery at an EC50 of 15 nM, with a maximal contraction 130% that of K+. A positive inotropic effect was found in strips of human atria (EC50 = 1 nM), which was not blocked by alpha- or beta-blockade. The widespread distribution of its binding sites suggests a more extensive role than control of vascular tone.
Animals↗
Multidimensionality of health status in an elderly population. Construct validity of a measurement battery.
Although health is generally accepted to be a multidimensional construct, the relationship among various domains has not been well defined. To understand this issue better we used principal components analysis to examine the relations among a set of health status measures gathered on 590 elderly members of a health maintenance organization (HMO). These included functional health, emotional health, social activity within and outside of the family, and cognitive functioning (all based on patient interview), physicians' ratings of patients' health, and chart-derived data on physiologic health. Support was obtained for the umbrella concept of "health" as well as for six subcomponents: functional health, emotional health, physiologic health, both kinds of social activity, and cognitive functioning. Patients' ratings of their overall physical and mental health were related to functional, physiologic, and emotional health factors, whereas physicians' ratings of overall physical and mental health were never related to the emotional health factor. This suggests that patients may hold a broader frame of reference in gauging overall health than physicians do.
Activities of Daily Living↗
Studies of doctor-patient interaction.
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Affect↗