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Showing papers by "University of Miami published in 1982"


Journal ArticleDOI
29 Oct 1982-Science
TL;DR: Monoclonal antibodies specific for 5-bromodeoxyuridine have been produced and applied in detecting low levels of DNA replication on a cell-by-cell basis in vitro and do not cross-react with thymidine.
Abstract: Monoclonal antibodies specific for 5-bromodeoxyuridine have been produced and applied in detecting low levels of DNA replication on a cell-by-cell basis in vitro. The immunoglobulin-producing hybridomas were derived from spleen cells of mice immunized with a conjugate of iodouridine and ovalbumin. The cells were fused with the plasmacytoma line SP2/0Ag14. The antibodies produced are highly specific for bromodeoxyuridine and iododeoxyuridine and do not cross-react with thymidine. DNA synthesis in cultured cells exposed to bromodeoxyuridine for as short a time as 6 minutes can be detected easily and rapidly by an immunofluorescent staining method and quantitated by flow cytometry.

2,722 citations


Journal ArticleDOI
TL;DR: The basic construct of control theory is presented—the discrepancy-reducing feedback loop—and certain of its implications for theory in three separate areas of human psychology are discussed, demonstrating the breadth of its applicability.
Abstract: Control theory provides a model of self-regulati on that we believe is useful in the analysis of human behavior. As an illustration of the breadth of its applicability, we present the basic construct of control theory—the discrepancy-reducing feedback loop—and discuss certain of its implications for theory in three separate areas of human psychology. In personality-s ocial, clinical, and health psychology, the construct proves to fit well with known phenomena and with the theories most recently developed to account for the phenomena. Moreover, in each case control theory appears to make a distinct and unique contribution to the state of the area. We conclude by noting the integrative potential that is suggested by these illustrations and by noting some issues that should receive attention in future work. Cybernetic or control theory is a general approach to the understanding of self-regulating systems. Its central ideas have been around for a long time (see, for example, Cannon's 1929, 1932, discussion of homeostatic physiological mechanisms), but its birth as a distinct body of thought is usually traced to the publication of Wiener's (1948) book, Cybernetics: Control and communication in the animal and the machine. Since then, control theory (in various forms) has had a major impact on areas of work as diverse as engineering (e.g., Dransfield, 1968; Ogata, 1970), applied mathematics (e.g.,

2,292 citations


Journal ArticleDOI
08 Oct 1982-Science
TL;DR: Human neonates (average age, 36 hours) discriminated three facial expressions posed by a live model as evidenced by diminished visual fixation on each face over trials and renewed fixations to the presentation of a different face.
Abstract: Human neonates (average age, 36 hours) discriminated three facial expressions (happy, sad, and surprised) posed by a live model as evidenced by diminished visual fixation on each face over trials and renewed fixations to the presentation of a different face. The expressions posed by the model, unseeen by the observer, were guessed at greater than chance accuracy simply by observing the face of the neonate, whose facial movements in the brow, eyes, and mouth regions provided evidence for imitation of the facial expressions.

780 citations


Journal ArticleDOI
TL;DR: Properties of the Ca‐activated K channel were studied in excised patches of surface membrane from cultured rat muscle cells using single channel recording techniques.
Abstract: 1. Properties of the Ca-activated K channel were studied in excised patches of surface membrane from cultured rat muscle cells using single channel recording techniques.2. Increasing the concentration of calcium at the intracellular membrane surface [Ca](i), increased both the frequency and effective duration of channel openings. Ca at the extracellular membrane surface was not sufficient to activate the channels.3. An approximate third power relationship (slope = 2.7) was observed between [Ca](i) and the percentage of time the channels spent in the open state.4. Both the frequency and effective duration of channel openings increased as the intracellular membrane surface was made more positive; the percentage of time spent in the open state increased e-fold for a 15 mV depolarization for low levels of activity.5. The percentage of time spent with 1, 2,...n channels open in membrane patches with n channels was described by the binomial distribution, suggesting that the channels opened and shut independently of one another.6. Single channel conductance (144 mM-K on both sides of the membrane) was essentially independent of membrane potential (-50 to +50 mV) and [Ca](i) (0.1 muM -1 mM), but did increase with temperature, from 100 pS at 1 degrees C to 300 pS at 37 degrees C.7. Channel activity occurred in apparent bursts, with the duration of the apparent bursts increasing with increasing [Ca](i).8. Two exponentials were required to describe the distribution of observed channel open times, suggesting two different open channel states of apparently normal conductance. The observed mean channel open time of these states at +30 mV was 0.34 and 2.2 msec with 0.1 muM-Ca(i) and was 0.47 and 6.9 msec with 0.5 muM-Ca(i).9. The channel occasionally entered an apparent third open channel state with a single channel current amplitude about 40% the amplitude of the normally observed single channel currents. The reduced conductance state was immediately preceded and followed by a normal conducting state.10. While the kinetics of the Ca-activated K channel appear complex, its large conductance and high Ca and voltage sensitivity suggest that it is uniquely suited to resist depolarizations of the cell membrane potential that are accompanied by increases in intracellular Ca.

718 citations


Journal ArticleDOI

585 citations


Journal ArticleDOI
01 Apr 1982-Nature
TL;DR: In this paper, a simple convection model driven by multiple turbulent buoyant plumes and observations of present deep water formation have led to the development of a theory for the formation of warm saline bottom water.
Abstract: Considerable isotopic evidence indicates that oceanic bottom water was much warmer in the geological past. A simple convection model driven by multiple turbulent buoyant plumes and observations of present deep water formation have led to the development of a theory for the formation of warm saline bottom water. It is suggested that changes in the size and configuration of marginal seas in net evaporation zones due to lithospheric plate motions and eustatic sea level change caused these seas to become sources of warm saline bottom water. Evidence from the palaeotemperature record and palaeogeography during the late Cretaceous is used to reinforce the hypothesis. Climatic and chemical consequences of the formation of warm saline bottom water are discussed.

365 citations


Journal ArticleDOI
TL;DR: Electrophysiological techniques are described which allow intracellular recording from peripheral myelinated axons of lizards and frogs for up to several hours, and show a prominent depolarizing afterpotential in isolated axons and in axons still attached to their peripheral terminals.
Abstract: 1. Electrophysiological techniques are described which allow intracellular recording from peripheral myelinated axons of lizards and frogs for up to several hours. The sciatic and intramuscular axons studied here have resting potentials of -60 to -80 mV and action potentials (evoked by stimulation of the proximal nerve trunk) of 50-90 mV. They show a prominent depolarizing afterpotential (d.a.p.), which is present both in isolated axons and in axons still attached to their peripheral terminals. This d.a.p. has a peak amplitude of 5-20 mV at the resting potential, and decays with a half-time of 20-100 msec.2. The peak amplitude of the d.a.p. is voltage-sensitive, increasing to up to 26 mV with membrane hyperpolarization. The d.a.p. disappears as the axon is depolarized to -60 to -45 mV, and does not appear to reverse with further depolarization.3. The d.a.p. is not reduced when bath Ca is replaced by 2-10 mm divalent Mn or Ni. The d.a.p. is not reversed when axons depleted of Cl (by prolonged exposure to Cl-deficient, SO(4)-enriched solutions) are bathed in Cl-rich solutions. These results suggest that the d.a.p. is not mediated by a conductance change specific for Ca or Cl ions. Partial substitution of tetramethylammonium for bath Na, or addition of 10(-5)m-tetrodotoxin to the normal bathing solution, reduces the amplitude of both the action potential and the d.a.p.4. The amplitude of the d.a.p. is not sensitive to bath [K] over the range 1-7.5 mm, provided that all measurements are made at the same holding potential. This result argues that the d.a.p. is not mediated by accumulation of K outside the active axon.5. Treatments expected to inhibit the Na-K exchange pump (cooling from 25 to 10 degrees C, or 0.15 mm-ouabain) do not enlarge or prolong the d.a.p., although they do abolish a slower hyperpolarizing afterpotential seen following repetitive stimulation.6. The passive voltage response of the axon to small injected pulses of depolarizing or hyperpolarizing current shows a prominent, slowly decaying component with a time course similar to that of the d.a.p. Depolarizing current reduces the input resistance of the axon, and increases the rate of decay of both the passive voltage response and the d.a.p. There is a slight conductance increase during the peak of the d.a.p., but the same conductance increase can be produced by a comparable passive depolarization.7. We conclude that the d.a.p. is due mainly to a passive capacitative current, probably resulting from discharge of the internodal axonal membrane capacitance through a resistive current pathway beneath or through the myelin sheath. We suggest that this slow capacitative discharge becomes evident as soon as most of the nodal ionic channels activated during the action potential have closed. An electrical model of the myelinated axon that incorporates the postulated internodal leakage pathway can account both for the prolonged d.a.p. recorded inside the axon, and for the potential profile recorded extra-axonally in or near the internodal periaxonal space.

356 citations



Journal ArticleDOI
TL;DR: In this paper, a set of scales, organized according to a cognitive-developmental framework and drawing upon recent research literature, is described in terms of its organization and content, and results that support the cognitive model underlying the sets of scales are reported.
Abstract: Interactional competencies that develop in the first two years of life provide a foundation for all further social and communicative developments. Their normal acquisition, especially in the handicapped, can not be taken for granted. If delays in social-communicative development can be identified early in life and changes made in how the social environment interacts with the child, intervention may effectively facilitate social development. However, to accomplish this, both a model for describing and an instrument for assessing interactional competencies are needed. A recently developed set of scales, organized according to a cognitive-developmental framework and drawing upon recent research literature, is described in terms of its organization and content. Results that support the cognitive model underlying the set of scales are reported. The paper concludes with a consideration of potential criticisms that may apply to such a theoretically based instrument.

292 citations


Journal ArticleDOI
01 Mar 1982-Cancer
TL;DR: Although survival was not expected to differ, it was predicted that functioning would be enhanced if quality of life improved, and it was concluded that enhancing the quality of survival for end‐stage cancer patients is a high priority medical goal.
Abstract: Much has been written about working with the dying. Few, if any, controlled studies have examined the application of principles set forth. The authors evaluate the effectiveness of working with dying cancer patients by assessing changes in quality of life, physical functioning, and survival. One-hundred twenty men with end-stage cancer were randomly assigned to experimental or control groups; the 62 experimental group patients were seen regularly by a counselor. Patients were assessed before random assignment and at one, three, six, nine, and 12 months on quality of live and functional status. Experimental group patients improved significantly more than the control group on quality of life within three months. Functional status and survival did not differ between groups. A subsample of lung cancer patients provided cross-validation of findings. Although survival was not expected to differ, it was predicted that functioning would be enhanced if quality of life improved. One interpretation is that little can be done to alter physical function and survival when intervention occurs late in the progression of a fatal disease. This in no way reduces the value of improving overall quality of life, since enhancing the quality of survival for end-stage cancer patients is a high priority medical goal.

256 citations


Journal ArticleDOI
TL;DR: In this article, the authors develop theory and algorithms for a multiplicative data envelope analysis (DEA) model employing virtual outputs and inputs as does the CCR ratio method for efficiency analysis.
Abstract: This paper develops theory and algorithms for a “multiplicative” Data Envelopment Analysis (DEA) model employing virtual outputs and inputs as does the CCR ratio method for efficiency analysis. The frontier production function results here are of piecewise log-linear rather than piecewise linear form.

Journal ArticleDOI
TL;DR: Intravitreal and subconjunctival injections of fluorouracil were well tolerated and may prove to be of significant value in the treatment of human disease.


Journal ArticleDOI
TL;DR: The histopathology and electron microscopic findings of an eye enucleated from a 67-year-old man with typical acute retinal necrosis showed profound acute necrosis of the retina, retinal arteritis, and eosinophilic intranuclear inclusions in retinal cells.

Journal ArticleDOI
TL;DR: The Penn Psychotherapy Project reports further progress in its search for the factors predicting the outcomes of psychotherapy through the construction of the Penn Helping Alliance Rating Method, based on two types of patients' statements during psychotherapy sessions.
Abstract: • The Penn Psychotherapy Project reports further progress in its search for the factors predicting the outcomes of psychotherapy through the construction of the Penn Helping Alliance Rating Method. This method is based on the following two types of patients' statements during psychotherapy sessions: type 1, that the therapist is helping the patient, and type 2, that the patient and therapist are working together in a team effort to help the patient. The scales were applied reliably to the transcripts from ten patients who had improved the most and ten who had improved the least among the 73 in the project. Significant predictive correlations were found for the early helping alliance measures (eg, with status at the termination of treatment and with the composite of "success, satisfaction, and improvement"). In contrast, other theoretically important treatment variables were not significant predictors.

Journal ArticleDOI
TL;DR: The results are compatible with the view that free radical reactions are initiated during ischemia, and that overt peroxidative processes become manifest during reflow when cerebral tissue is reoxygenated.

Journal ArticleDOI
TL;DR: The acute retinal necrosis syndrome is characterized by necrotizing retinitis, vitritis, and retinal vasculitis occurring in otherwise healthy patients as mentioned in this paper, and the natural history, diagnosis, postulated etiology, and suggestions for management are discussed.

Journal ArticleDOI
TL;DR: A revised version of the Rapid Disability Rating Scale (RDRS‐2) is presented, and the new appraisals of reliability, factor structure, and validity are reported, along with the potential uses of the scale.
Abstract: A revised version of the Rapid Disability Rating Scale (RDRS-2) is presented. Item definitions have been sharpened and directions expanded to indicate that ratings are based upon the patient's performance in regard to behavior, and that prostheses normally used by the patient should be included in the assessment. Three items have been added to increase the breadth of the scale. Response items have been changed from three-point to four-point ratings in order to increase group discrimination and make the scale more sensitive to changes in treatment. The new appraisals of reliability, factor structure, and validity are reported, along with the potential uses of the scale.

Journal ArticleDOI
01 Dec 1982-Nature
TL;DR: Hole 504B provides a reference section for correlation of in situ petrological and geophysical studies with regional crustal models based on dredged samples and remote surveys; and, at least for the medium spreading-rate Costa Rica Rift, Hole 504B confirms that the main features of the upper part of an idealized ophiolite sequence occurs in the oceanic crust as mentioned in this paper.
Abstract: Hole 504B provides a reference section for correlation of in situ petrological and geophysical studies with regional crustal models based on dredged samples and remote surveys; and, at least for the medium-spreading-rate Costa Rica Rift, Hole 504B confirms that the main features of the upper part of an idealized ophiolite sequence occurs in the oceanic crust.

Book ChapterDOI
TL;DR: The biochemical mechanism by which the reaction of estradiol and other estrogenic hormones with receptor substances elicits hormonal response has been the subject of extensive investigation and appears to be characteristically restricted in hormone-dependent tissues.
Abstract: Publisher Summary The original discovery of steroid hormone receptors and essentially all information concerning their interaction and function in target cells have depended on experiments in which a radioactive steroid serves as a marker for the receptor protein to which it binds The female reproductive tissues, such as uterus, vagina, and anterior pituitary, contain a characteristic estrogen-binding component which was first indicated by their striking ability to take up and retain tritiated hexestrol and estradiol after the administration of physiological doses of these substances to immature animals This chapter discusses the biochemical mechanism by which the reaction of estradiol and other estrogenic hormones with receptor substances elicits hormonal response has been the subject of extensive investigation The activated steroid-receptor complex is translocated to the nucleus where it binds to chromatin and in some way modulates RNA synthesis which appears to be characteristically restricted in hormone-dependent tissues

Journal ArticleDOI
TL;DR: This paper showed that a reliability coefficient calculated from the formula can be high, provided one makes other assumptions about the values of pretest and posttest reliability coefficients and standard deviations and there is reason to believe that the revised assumptions are more realistic than the usual ones in testing practice.
Abstract: Many investigators have concluded that difference scores and gain scores, such as differences between pretest and posttest measures resulting from an experimental treatment or period of instruction, have questionable value in research in part because of their low reliability (e.g., Linn & Slinde, 1977; Lord, 1963; O'Connor, 1972). Cronbach and Furby (1970, p. 80) recommended that "... investigators who ask questions regarding gain scores ... frame their questions in other ways." These conclusions are based on certain assumptions which at first glance appear reasonable about the values of parameters in a well known formula for the reliability of differences. (See, for example, Lord, 1963.) In this paper we will show that a reliability coefficient calculated from the formula can be high, provided one makes other assumptions about the values of pretest and posttest reliability coefficients and standard deviations. Furthermore, there is reason to believe that the revised assumptions are more realistic than the usual ones in testing practice.

Journal ArticleDOI
TL;DR: The effects of multiple scattering on the interpretation of the time dependence of elastic backscattering of laser pulses from the ocean (lidar) are investigated through solving the radiative transfer equation by Monte Carlo techniques.
Abstract: The effects of multiple scattering on the interpretation of the time dependence of elastic backscattering of laser pulses from the ocean (lidar) are investigated through solving the radiative transfer equation by Monte Carlo techniques. In particular, after removal of the geometric loss factors, it is found that the backscat-tered power is a decaying exponential function of time, over the time interval required for photons to travel four attenuation lengths through the water. The effective attenuation coefficient of this exponential decay is found to be strongly dependent on the parameters of the lidar system and on the optical properties of the water. The significant parameter is the ratio of the radius of the spot on the sea surface viewed by the lidar receiver optics to the mean free path of photons in the water. For values of this parameter near zero, the decay is determined by the beam attenuation coefficient, while for values greater than ~5-6, the decay is given by the attenuation coefficient for downwelling irradiance, often referred to as the diffuse attenuation coefficient. Between these two extremes the interpretation of the effective attenuation coefficient requires, essentially, complete knowledge of the inherent optical properties of the water: the beam attenuation coefficient and the volume scattering function.

Journal ArticleDOI
TL;DR: Observations of conjugated dienes in vivo and in vitro indicate that lipid radical intermediates and associated chain peroxidation processes are potentiated by ischemia and occur during tissue reoxygenation.
Abstract: Post-ischemic changes in energy metabolites and natural antioxidant compounds have been measured in rat brain in vitro concurrent with two different assays for peroxidized lipids. No exogenous free radical initiators were employed. In vitro oxygenation of minced brain preparations for periods of 10 minutes to 4 hours, following 5 minutes of preparatory ischemia, yielded increased levels of lipid conjugated dienes and TBA-reactive material, in contrast to anaerobically incubated preparations. However, either aerobic or anaerobic incubation of brain minces facilitated increased ratios of lactate: pyruvate and glutathione (oxidized): glutathione (reduced), as well as increased total ubiquinone content and loss of α-tocopherol. Observation of lipid radical formation in vivo was then attempted using rats given embolic stroke in one hemisphere and left in the post-ischemic condition for times up to 24 hours. Conjugated dienes were found in lipids extracted from the ipsilateral hemisphere but not from the contralateral hemisphere. These observations of conjugated dienes in vivo (formed presumably during post-ischemic reperfusion) and in vitro (facilitated by oxygenation of brain minces), indicate that lipid radical intermediates and associated chain peroxidation processes are potentiated by ischemia and occur during tissue reoxygenation.

Journal ArticleDOI
TL;DR: The carbonic anhydrase activity associated with particulate fractions of homogenates of rat, rabbit, human, and bovine lungs appears to be a new isozyme whose properties are consistent with such a localization.


Journal ArticleDOI
TL;DR: The previously advanced hypothesis that desiccation resistance involves the replacement of water adjacent to intracellular surfaces with polyhydroxy compounds has been supported by experiments on cysts of the brine shrimp, Artemia, and in a model system of albumin--glycerol--water, using nuclear magnetic resonance spectroscopy, microwave dielectrics, and density measurements.

Book ChapterDOI
01 Jan 1982
TL;DR: This chapter will discuss the present knowledge of the foraging strategies of plant-visiting bats and will be minimally concerned with the potential consequences of chiropteran foraging behavior on plant populations.
Abstract: Approximately 250 of the 850 known species of bats (about 29%) are partially or wholly dependent upon plants as a source of food. These bats are involved in a mutualistic exploitation system with plants in which the bats obtain food in the form of nectar, pollen, or fruit while providing mobility for the plant’s pollen grains or seeds. Coevolutionary aspects of these bat-plant interactions are discussed in detail (Chapter 9). In this chapter I will discuss our present knowledge of the foraging strategies of plant-visiting bats and will be minimally concerned with the potential consequences of chiropteran foraging behavior on plant populations.

Journal ArticleDOI
01 Jan 1982-Toxicon
TL;DR: The purification and crystallization of T17, a toxin from Ptychodiscus brevis, is reported and is believed to be the agent responsible for Neurotoxic Shellfish Poisoning.

Journal ArticleDOI
TL;DR: Patients with urinary incontinence from a wide variety of causes with periurethral polytetrafluoroethylene injections have been treated with good to excellent results and the procedure is well tolerated.

Journal ArticleDOI
TL;DR: Of the 9 chemicals tested after metabolic activation by liver microsomal S9 preparation, significant increases in SCE frequency were seen in diazinon-, dimethoate-, Dursban- and Phosdrin-treated cells.
Abstract: In the present study, cytotoxic, cytostatic and cytogenetic effects of a number of organophosphate pesticides on human lymphoid cells (LAZ-007) in culture have been examined. Cytotoxic effects were dose related and often led to extensive cell kill. The pronounced effects of various organophosphates on the cell-cycle traverse were shown in data based on the enumeration of M 1 and M 3 metaphases after incubation of cells with BrdU. In cells incubated with 20 μg/ml of the various chemicals, the number of M 1 metaphases ranged from 6% (R-1303) to 18% (Azodrin) compared to no M 1 metaphases in control cultures. The number of M 3 s in cultures treated with 20gmg/ml of the various chemicals tested varied from 0% (Phosdrin) to 7% (parathion) as compared to 17% in control cultures. 11 out of the 14 organophosphates tested, significantly increased the SCE frequency. Of the 9 chemicals tested after metabolic activation by liver microsomal S9 preparation, significant increases in SCE frequency were seen in diazinon-, dimethoate-, Dursban- and Phosdrin-treated cells.