Showing papers by "University of Pittsburgh published in 1971"
TL;DR: An attempt has been made to direct the evolution of critical care medicine based on the author's personal experiences with the development of emergency care and intensive care programs during the past decade, and on review of the available literature.
2,051 citations
TL;DR: A rapid and simple method for the measurement of serum “estrogen” concentrations is described which provides a good approximation of estradiol levels.
Abstract: Estradiol and LH levels were measured by radioimmunoassay in daily samples of peripheral serum of rhesus monkeys during 10 normal menstrual cycles. During the 4 days prior to the LH surge, serum estradiol values rose sharply, while the LH levels declined. The midcycle peak of estradiol and LH occurred simultaneously in 9 of the 10 cycles studied. These peaks were followed within 24 to 48 hr by an abrupt fall in estradiol levels, while LH levels declined over a 5-day period. Most animals showed no luteal phase peaks in serum estradiol concentration. A rapid and simple method for the measurement of serum “estrogen” concentrations is described which provides a good approximation of estradiol levels. (Endocrinology 89:177, 1971)
576 citations
TL;DR: Cardiac myofibrils treated with 1% Triton X-100 are virtually free of contamination by mitochondrial, sarcolemmal and sarcoplasmic reticular membranes and the ATPase activity corresponds closely to that reported for cardiac actomyosin.
406 citations
TL;DR: The semi-micro method for interferon assay was based on quantitation of inhibition of cytopathic effects in 6-mm wells and was more sensitive than the plaque-inhibition method and was extremely economical.
Abstract: Mostmethods ofinterferon assay, suchas plaque inhibition andyield reduction, areexpensive interms oftimeandmaterials. Lesscomplex methods, suchasinhibition ofcytopathic effects (CPE), tendtobesubjective anddifficult to quantitate. Finter (1)hasdescribed howcytopathology maybequantitated bytheuptake and elution ofavital dyeandhasapplied this technique totheassay ofinterferon. A micro-method fortitration ofhumanandchick interferon was described byTiles andFinland (4)whobased interferon activity on inhibition ofCPE,as observed inthemicroscope oron metabolic inhibition. This paper describes theassay ofrabbit interferon byasemi-micro, dye-binding method whichisextremely economical, especially in respect tocell culture materials andinterferon samples.
303 citations
TL;DR: It appears that the Na influx that is coupled to the influxes of amino acids and sugars is electrogenic and responsible for the depolarization of ψmc, which is seen in tissues poisoned with metabolic inhibitors or ouabain.
Abstract: When isolated strips of mucosal rabbit ileum are bathed by physiological electrolyte solution the electrical potential difference (PD) across the brush border (ψmc) averages 36 mv, cell interior negative. Rapid replacement of Na in the mucosal solution with less permeant cations, Tris or choline, results in an immediate hyperpolarization of ψmc. Conversely, replacement of choline in the mucosal solution with Na results in an abrupt depolarization of ψmc. These findings indicate that Na contributes to the conductance across the brush border. The presence of actively transported sugars or amino acids in the mucosal solution brings about a marked depolarization of ψmc and a smaller increase in the transmural PD (Δψms). It appears that the Na influx that is coupled to the influxes of amino acids and sugars is electrogenic and responsible for the depolarization of ψmc. Under control conditions Δψms can be attributed to the depolarization of ψmc together with the presence of a low resistance transepithelial shunt, possibly the lateral intercellular spaces. However, quantitatively similar effects of amino acids on ψmc are also seen in tissues poisoned with metabolic inhibitors or ouabain. Under these conditions Δψmc is much smaller than under control conditions. Thus, the depolarization of ψmc might not account for the entire Δψms, observed in nonpoisoned tissue. An additional electromotive force which is directly coupled to metabolic processes might contribute to the normal Δψms.
274 citations
TL;DR: The line absorption technique was applied to the kinetic study of the two metastable atomic nitrogen states N (22D) and N(22P) in a flowing afterglow system.
Abstract: The line absorption technique was applied to the kinetic study of the two metastable atomic nitrogen states N (22D) and N (22P) in a flowing afterglow system. The optical absorptions of the NI 1493‐A (2p32D−3s2P) and 1743‐A (2p32D−3s2P) transitions were used for the quantitative measurement of N (22D) and N (22P) concentrations. Deactivation of N (2D) and N (2P) by the Pyrex tube wall was found to be very efficient, i.e., occurs at nearly every collision. The second‐order rate constants at 300°K for the removal of N (2D) by O2, N2O, CO2, NO, N2, Ar, and He were found to be (6±2)×10−12, (3.5±1.2)×10−12, (5±2)×10−13, (7±2.5)×10−11, (1.6±0.7)×10−14, (1±0.6)×10−16, and ≤ 1.6×10−16 cm3 sec−1, respectively. It was established that the process for the first three reactant gases results in chemical reaction rather than physical quenching.
255 citations
TL;DR: In this article, a general framework for studying differential operations in renormalized perturbation theory is derived, which makes possible a simple unified derivation of the renormalization group and Callan-Symanzik equations, as well as a direct test for broken symmetries (including broken scale invariance), without the necessity of defining currents and deriving their generalized Ward identites.
Abstract: A general framework is derived for studying differential operations in renormalized perturbation theory. The method makes possible a simple, unified derivation of the renormalization group and Callan-Symanzik equations, as well as a direct test for broken symmetries (including broken scale invariance), without the necessity of defining currents and deriving their generalized Ward identites. A second-order differential equation of the Callan-Symanzik type is derived using similar methods.
234 citations
TL;DR: Colonies of eosinophils, neutrophils, monocytes, and macrophages grown in vitro from peripheral leukocytes of normal individuals revealed that all colonies examined contained labeled cells, indicating that these colonies arose from cell proliferation.
204 citations
TL;DR: Direct correlation of externally measured systolic time intervals with internally measured indices was obtained using catheter-tip micromanometers in six patients who had normal coronary arteriograms.
Abstract: Direct correlation of externally measured systolic time intervals with internally measured indices was obtained using catheter-tip micromanometers in six patients who had normal coronary arteriograms. Simultaneous recordings were made of central aorta and left ventricular pressure, maximum rate of rise in left ventricular pressure (dp/dt), external carotid pulse, external and internal sound, and electrocardiogram. Acute interventions were used to vary the indices by a variety of mechanisms including changes in contractility, preload, afterload, and heart rate. The initial values and the changes in these values produced by acute interventions are identical for left ventricular ejection time (LVET) whether measured externally (range 175 to 385 msec) or internally (range 169 to 392), r = 0.99. Although the absolute values differed for internally measured isovolumic contraction time (internal ICT), externally measured ICT, and preejection time (PEP), there was good linear correlation between the changes obser...
199 citations
191 citations
TL;DR: In this paper, a general theory of elastoplastic flow is formulated for work-hardening materials that may be both anisotropic and compressible, and the theory is cast in terms of integral equations and the result is an extended form of Somigliana's identity.
TL;DR: Serum luteinizing hormone levels were determined every 15 minutes, between 6:00 a.
Abstract: Serum luteinizing hormone (LH) levels were determined every 15 minutes, between 6:00 a. m. and 6:00 p. m., in four normally active men. Each subject demonstrated a repetitive pattern of abrupt elevations throughout the day. Twenty-one elevations were found during the total of 48 hours of monitoring. In the four volunteers, ratios of the highest to lowest levels of gonadotropin during the 12 hours ranged from 2.1–2.9. Individual or averaged concentrations of LH may not completely characterize pituitary-gonadal relationships.
TL;DR: It was demonstrated, by use of extracorporeal cross-circulation, that a humoral factor responsible for liver regeneration does not arise from the liver remnant and that the onset of regeneration is the result of a quantitative imbalance between the available portal blood factor and the number of liver cells present.
Abstract: It was demonstrated, by use of extracorporeal cross-circulation, that a humoral factor responsible for liver regeneration does not arise from the liver remnant. While intact livers of normal rats incorporated [methyl-(3)H]- thymidine in proportion to the amount of liver removed in the partner, the greatest response occurred after a total hepatectomy. Evidence from portacaval-shunted,partially hepatectomized animals connected to normal members indicates that the factor is in portal blood and that the onset of regeneration is the result of a quantitative imbalance between the available portal blood factor and the number of liver cells present.
TL;DR: Human leukemic cells with a marker (Philadelphia; Ph1) chromosome gave rise to granulocytic and mononuclear cell colonies when grown in vitro, suggesting that leukeMIC and normal cells exist simultaneously and that in vitro colonies are clonal in origin.
Abstract: Human leukemic cells with a marker (Philadelphia; Ph(1)) chromosome gave rise to granulocytic and mononuclear cell colonies when grown in vitro. All metaphases from a single colony were either Ph(1) positive or Ph(1) negative. No colonies contained a mixed cell population. This suggests that leukemic and normal cells exist simultaneously and that in vitro colonies are clonal in origin.
TL;DR: In this paper, absolute transition probabilities have been derived for the N21P and the N+2M systems for both the N22P and N+21N systems, compiled from earlier measurements, to provide a complete set for the four systems.
Abstract: Quantitative optical measurements of the N21P,2P and N+21N and Meinel systems, excited by electrons, have allowed measurements of transition probabilities, excitation cross-sections, and afterglow effects. This work is reported in two parts. The experiment and observations are described in detail in this article. Absolute transition probabilities have been derived for the N21P and the N+2M systems. Tables of values for the N22P and N+21N systems, compiled from earlier measurements, are included to provide a complete set for the four systems.
TL;DR: In this article, the electron impact on CO2 has been used to produce vacuum ultraviolet multiplets of C I, C II, and O I. The dependence of the excitation functions on electron energy shows that these multiplets are produced by electric-dipole-allowed transitions in CO2.
Abstract: Vacuum ultraviolet multiplets of C I, C II, and O I were produced by electron impact on CO2. Absolute emission cross sections for these multiplets were measured from threshold to 350 eV. The electrostatically focused electron gun used is described in detail. The atomic multiplets which were produced by dissociative excitation of CO2 and the cross sections at 100 eV are presented. The dependence of the excitation functions on electron energy shows that these multiplets are produced by electric-dipole-allowed transitions in CO2.
TL;DR: It is concluded that the “trigger” for LH discharge, in the rhesus monkey, consists of an effective increment in circulating estrogen levels which must be maintained for at least 12 hr and that this positive feedback action of the steroid is clearly operative only in nonlactating adult females.
Abstract: Subcutaneous injections of estradiol benzoate in oil, resulting in a sustained elevation of circulating estrogen levels, induced LH discharges markedly similar to the spontaneous preovulatory LH surges observed during the normal menstrual cycle. Exogenous estrogen leading to high plasma estrogen concentrations for brief periods (less than 12 hr) was ineffective in this regard. The discharge of LH in response to estrogen administration was observed in cycling and in ovariectomized females but not in intact males or in lactating females. It is concluded that the “trigger” for LH discharge, in the rhesus monkey, consists of an effective increment in circulating estrogen levels which must be maintained for at least 12 hr and that this positive feedback action of the steroid is clearly operative only in nonlactating adult females. (Endocrinology 89: 1034, 1971)
TL;DR: Using a quantitative bioassay technique, a cyclic variation in pineal melatonin content was monitored in laboratory rats and two species of birds and the oscillation was found to bear a consistent phase relationship to that of cyclic changes in environmental illumination.
01 May 1971
TL;DR: The properties of Sex pili, the Viral Nature of “Conjugal” Genetic Transfer Systems, and some possible Approaches to the Control of Bacterial Drug Resistance are discussed in this paper.
Abstract: (1971). The Properties of Sex pili, The Viral Nature of “Conjugal” Genetic Transfer Systems, and Some Possible Approaches to the Control of Bacterial Drug Resistance. CRC Critical Reviews in Microbiology: Vol. 1, No. 1, pp. 105-160.
TL;DR: A rhythm of pineal melatonin content persists and is phase-locked with the free-running, circadian rhythm of locomotor activity, however, the melatonin cycle was suppressed in intact rats that were maintained in continuous light.
Abstract: Male rats that were maintained in continuous darkness or blinded by enucleation exhibited circadian rhythms of wheel-running activity. Pineal bodies taken from rats that were killed during the phase of greater locomotor activity contained significantly more melatonin than the pineal bodies of rats killed during the phase of lesser activity. Thus, a rhythm of pineal melatonin content persists and is phase-locked with the free-running, circadian rhythm of locomotor activity. However, the melatonin cycle was suppressed in intact rats that were maintained in continuous light. (Endocrinology 89: 1361, 1971)
TL;DR: It is indicated that the regional lymph node is more important in the development of tumor immunity than in production of transplantation or hypersensitivity response and the role of the bloodstream in host sensitization to tumor.
Abstract: Utilizing a syngeneic tumor-host system, the role of the regional lymph node in initiating immunity to tumor was evaluated. In the absence of regional lymph nodes, no apparent sinecomitant nor concomitant immunity developed despite the presence of a growing immunizing tumor for as long as 28 days. Findings minimize the role of the bloodstream in host sensitization to tumor. They provide another possible explanation as to why an antigenic tumor may arise de novo in an immunologically normal host, and they indicate that the regional lymph node is more important in the development of tumor immunity than in production of transplantation or hypersensitivity response.
TL;DR: In this article, the fourth positive band system excitation cross sections by electron impact on carbon monoxide and carbon dioxide were analyzed for carbon dioxide, carbon dioxide and CO 2, respectively.
Abstract: CO Fourth Positive band system excitation cross sections by electron impact on carbon monoxide and carbon dioxide
TL;DR: In this article, a technique for quantizing currents in Lagrangian field theory was developed with the aid of Zimmermann's normal products, which greatly simplify the derivation of single-current generalized Ward identities and may be used to justify the heuristic use of formal arguments in discussing broken symmetries.
Abstract: Techniques for quantizing currents in Lagrangian field theory are developed with the aid of Zimmermann's normal products. These methods greatly simplify the derivation of single-current generalized Ward identities and may be used to justify the heuristic use of formal arguments in discussing broken symmetries. Applications to the energy-momentum tensor in the ${A}^{4}$ model and to the current of broken orthogonal symmetry in a two-component scalar model are presented.
TL;DR: This finding may be significant, in that it indicates a terminal failure in increased placental progesterone genesis, at a time when the continued increase in uterine volume promotes myometrial activity through a stretch effect.
TL;DR: Experimental techniques for differential, total and momentum transfer electron-molecule scattering cross sections at low electron energies, discussing rotational excitation are described in this article. But the experimental results are limited.
Abstract: Experimental techniques for differential, total and momentum transfer electron-molecule scattering cross sections at low electron energies, discussing rotational excitation
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01 May 1971
TL;DR: In this article, the authors presented heat capacity data for the five LnAl 2 compounds, where Ln=La, Ce, Pr, Nd and Gd, in approximate agreement with R In (2 J + 1) except for GdAl 2 in which the discrepancy was about 25 percent.
TL;DR: Electron microscopic study has revealed distinctly different granules in cells comprising alveolar soft part sarcoma, carotid body tumor (nonchromaffin paraganglioma), malignant melanoma, and granular cell myoblastoma which allow for their differential diagnosis, militate against views that implicate a histogenetic relationship between alveolars soft part Sarcoma and anatomical analogues of these alveolated neoplasms or those of neutral origin.
Abstract: Electron microscopic study has revealed distinctly different granules in cells comprising alveolar soft part sarcoma, carotid body tumor (nonchromaffin paraganglioma), malignant melanoma, and granular cell myoblastoma which allow for their differential diagnosis. This, as well as other pertinent information, militate against views that implicate a histogenetic relationship between alveolar soft part sarcoma and anatomical analogues of these alveolated neoplasms or those of neutral origin. On the other hand, the cytoplasmic crystalloids encountered in alveolar soft part sarcoma exhibit a striking morphological similarity to the rods observed in cells of benign rhabdomyoma and nemaline myopathy as well as Z‐band material and tropomyosin B. Differences noted between these structures, as well as rods observed in examples of alveolar or pleomorphic rhabdomyosarcoma, do not appear sufficiently significant to compromise the conclusion that the alveolar soft part sarcoma most likely represents a unique type of rhabdomyosarcoma.
TL;DR: In this article, a comparison between 100 children of alcoholics and 100 non-alcoholics was made and the findings indicated that children of alcoholic children have a high risk for development of social problems and are at risk for depression.
Abstract: Comparisons were made between 100 children of alcoholics and 100 of nonalcoholics. The findings indicated that children of alcoholics have a high risk for development of social problems and are thu...