Showing papers by "Tulane University published in 1976"
TL;DR: The present results indicate that two subpopulations of primary sensory neurons exist, one containing somatostatin, or som atostatin-like immunoreactivity, and the other containing substance P, or substance P-like Immunoreactivity.
740 citations
TL;DR: A thermomechanical continuum theory involving a chemical reaction and mass transfer between two constituents is developed in this article as a model for bone remodeling, which describes an elastic material which adapts its structure to applied loading.
Abstract: A thermomechanical continuum theory involving a chemical reaction and mass transfer between two constituents is developed here as a model for bone remodeling. Bone remodeling is a collective term for the continual processes of growth, reinforcement and resorbtion which occur in living bone. The resulting theory describes an elastic material which adapts its structure to applied loading.
659 citations
TL;DR: The chemiluminescent response obtained was of high intensity, and could be easily monitored using the standard in-coincidence scintillation spectrophotometry equipment employed in routine isotope counting.
564 citations
TL;DR: Intravenous injection of sheep antiserum to somatostatin in the rat not only increases basal plasma TSH levels but also potentiates TSH response following exposure to cold, which suggests the involvement of GH-releasing hormone, in addition to som atostatin, in the GH release mechanism.
240 citations
TL;DR: Operative measures which permanently interrupted the innominate artery in the area of possible future erosion were the most successful and all personnel providing care for patients with tracheostomies should be aware of the initial measure of balloon inflation.
Abstract: Successful management of a patient with tracheo-innominate artery erosion requires the rapid institution of specific resuscitative and operative measures Ten patients seen at the Charity Hospital of Louisiana in New Orleans and 127 documented cases from the world literature were analyzed regarding predisposing factors, diagnostic features, resuscitative measures and operative treatment Diagnoses associated with abnormal neck positioning were seen in 48% of patients with tracheo-innominate erosions In 69% of 96 instances, the site of erosion was located at the cannula end and implicates excessive anterior pressure Caution is recommended in those patients with abnormal neck positions, low placed tracheostomy stomas and individuals with asthenic habitus Resuscitative measures were highly successful when the tracheal ballon was inflated or when the method of retrosternal finger pressure was used All personnel providing care for patients with tracheostomies should be aware of the initial measure of ballon inflation Operative measures which permanently interrupted the innominate artery in the area of possible future erosion were the most successful Of the 22 cases in which the innominate artery was sacrificed, only one had evidence of cerebral ischemia Timely institution of proper measures can result in salvage of an unexpected number of these otherwise dramatic fatalities
220 citations
TL;DR: In this paper, it was shown that a femur will not undergo bone remodeling as a result of a pure torsion about the long axis of the bone, but rather due to a pure curvature of the femur.
Abstract: The general theory of adaptive elastic materials proposed in [1] as a model for the physiological process of bone remodeling is specialized to the case of small strains in isothermal processes. Boundary value problems in the context of this specialized theory are specified and solved. It is shown that remodeling will not occur in a long bone such as a femur as a result of a pure torsion about the long axis of the bone. Criteria for biologically normal remodeling are established for steady stress and steady strain.
191 citations
TL;DR: The electrocardiograms of 65 patients with the "early repolarization syndrome" (normal variant of RS-T elevation) were analyzed to delineate the features and evaluate the natural history of this Electrocardiographic entity.
Abstract: The electrocardiograms of 65 patients with the "early repolarization syndrome" (normal variant of RS-T elevation) were analyzed to delineate the features and evaluate the natural history of this electrocardiographic entity. Maximal follow-up was 26 years. The syndrome was characterized by (1) an upward concave elevation of the RS-T segment with distinct or "embryonic" J waves, slurred downstroke of R waves or distinct J points or both; (2) RS-T segment elevation commonly encountered in the precordial leads and more distinct in these leads; (3) rapid QRS transition in the precordial leads with counterclockwise rotation; and (4) persistence of these characteristics for many years although some intraindividual changes were common. Less commonly found were (5) tall R and T waves in the precordial leads; (6) "labile" or "juvenile" T wave patterns; (7) "pseudo-R" waves; and (8) "isolated T negativity syndrome." These changes commonly simulate pericarditis, myocardial ischemia, left ventricular hypertrophy and right bundle branch block.
173 citations
TL;DR: It was concluded that the stress-induced decrease of GH secretion in rats is at least partly due to an increased release of hypothalamic somatostatin and/or immunologically related GH release-inhibiting hormone(s).
Abstract: To investigate the physiological role of somatostatin in the GH release mechanism, the effect of passive immunization with somatostatin on basal and poststress serum GH levels was examined in rats. Sheep antiserum to somatostatin or normal sheep serum (NSS) was injected iv into adult male rats 5 days, 3 days and 1 day before applying stressful stimuli. Thirty min after the first bleeding under ether, the mean serum GH level increased from 36.3 to 76.1 ng⁄ml in the antiserum-treated rats and decreased from 63.7 to 16.8 ng⁄ml in the NSStreated rats, but the difference for either group was not significant due to the large variation. In another experiment, electroshock was applied to conscious rats. The mean poststress GH level in the rats pre-treated 3 h previously with the antiserum was 34.4 ng⁄ml, a value significantly higher than the GH level in the rats pretreated with NSS (0.9 ng⁄ml) or in non-treated rats (0.5 ng⁄ml). It was concluded that the stress-induced decrease of GH secretion in rats is at least...
172 citations
TL;DR: PCP was shown to be a potent, competitive inhibitor of both 3 H-dopamine uptake in the striatal region and3 H-norepinephrine uptake inThe hypothalamus, suggesting a drug-induced imbalance of the catecholaminergic-cholinergic systems in those regions of the brain where activity has been correlated with emotional expression.
158 citations
01 Jan 1976
TL;DR: A study of epistemology, one which has been made from a realistic standpoint, is called ‘adaptive knowing’, because it describes the various moves made by the individual in his efforts to cope with knowledge.
Abstract: You are about to read a study of epistemology, one which has been made from a realistic standpoint. It is not the first of such interpretations, and it will not be the last. The special thesis that distinguishes this realistic epistemology from the others is called ‘adaptive knowing’, because it describes the various moves made by the individual in his efforts to cope with knowledge. It assumes that there is a feedback from knowledge which conditions further learning. It assumes also that the cognitive process is a stage process, and that the stages are those involving the acquisition, the assimilation, and the deployment of knowledge.
TL;DR: Recognition of the attributes of biliary recycling also helps to explain the observed variability in apparent plasma half-life, while their neglect requires alternative explanations for anomalies between the disappearance rate from plasma and the corresponding appearance rate in urine.
Abstract: There are no discernible quantitative differences in the biotransformation and the excretion of indomethacin following oral, rectal, and intravenous administration of indomethacin-14C. Approximately 50% (range 24–115% for n=6) of an intravenous dose undergoes enterohepatic circulation. Thus the bioavailability of indomethacin to the systemic circulation may exceed the administered dose. Relative to the intravenous dose, indomethacin is 80 and 100% bioavailable from suppositories and capsules, respectively. Absorption and/or reabsorption appears to be more rapid and uniform by the rectal route. Recognition of the attributes of biliary recycling also helps to explain the observed variability in apparent plasma half-life, while their neglect requires alternative explanations for anomalies between the disappearance rate from plasma and the corresponding appearance rate in urine.
TL;DR: The finding that GH-RIH inhibits gastric secretion induced by exogenous stimulants as well as by the direct chemical stimulation of the HP mucosa without changing serum gastrin level suggests that the major action of GH- RIH is a direct suppression of the oxyntic glands.
TL;DR: The incorporation of simple d-amino acids in place of glycine in position 6 of the LH-RH decapeptide produces analogs which have far greater gonadotropin-releasing activities in vivo and in vitro than the natural hormone.
Abstract: The incorporation of simple d-amino acids in place of glycine in position 6 of the LH-RH decapeptide produces analogs which have far greater gonadotropin-releasing activities in vivo and in vitro than the natural hormone. An investigation of the structural features of the d-amino acids responsible for this phenomenon suggests that an increase in the lipophilic character and perhaps the size and aromaticity of the side chain coincides with an increase in biological activity. This is demonstrated by the LH-releasing activities of the following series of peptides which were assayed over a period of 6 h in immature male rats: [d-Glu(6)]-,1.8;[d-Ala(6)]-,7.0;[d-Leu(6)]-,9,0;[d-Phe(6)]-,10;[d-Trp(6)]-LH-RH, 13 times more active than LH-RH itself. In contrast to previous results with [d-Ala(6)]-and [d-Leu(6)]-LH-RH, where the substitution of an ethylamide group for the glycine amide at the C-terminus produces large increases in LH/FSH releasing activity, the ethylamide derivatives of [d-Phe(6)]-and [d-Trp(6)]-LH-RH were actually less potent than their parent peptides. [(N-Me-d-Ala)(6)]-LH-RH was found to be approximately 70 times less active than [d-Ala(6)]-LH-RH which indicates that disruption of a preferred receptor-site binding conformation might be brought about by methylation of the amide linkage in this position.
TL;DR: The stabilization of the β-bend conformation of methionine5-enkephalin by the substitution of D-alanine in position 2 of the peptide chain may contribute to the high activities of the [D-Ala2]-analogs.
Book•
01 Jan 1976TL;DR: The relationship between food and ceremony was discussed in the Harvard University Press edition of "The Relationship between Food and Ceremonies" as discussed by the authors, with a focus on food and ceremonies.
Abstract: Reprint of the Harvard University Press edition originally published in 1976 on the relationship between food and ceremony. Annotation copyright Book News, Inc. Portland, Or.
TL;DR: The metabolism of aspartame has been studied in mice, rats, rabbits, dogs, monkeys, and humans and the compound was digested in all species in the same way as are natural constituents of the diet.
Abstract: Aspartame [SC-18862; 3-amino-N-(alpha-carboxyphenethyl) succinamic acid, methyl ester, the methyl ester of aspartylphenylalanine] is a sweetening agent that organoleptically has about 180 times the sweetness of sugar. The metabolism of aspartame has been studied in mice, rats, rabbits, dogs, monkeys, and humans. The compound was digested in all species in the same way as are natural constituents of the diet. Hydrolysis of the methyl group by intestinal esterases yielded methanol, which was oxidized in the one-carbon metabolic pool to CO2. The resultant dipeptide was split at the mucosal surface by dipeptidases and the free amino acids were absorbed. The aspartic acid moiety was transformed in large part to CO2 through its entry into the tricarboxylic acid cycle. Phenylalanine was primarily incorporated into body protein either unchanged or as its major metabolite, tyrosine.
TL;DR: It is demonstrated that enkephalin and some of its analogs can exert significant behavioral changes after IP administration and that these behavioral effects probably can be dissociated from the opiate effects.
Abstract: Met-enkephalin and its analog [D-Ala2]-Met-enkephalin-NH2 were administered intraperitoneally (IP) at a dose of 80 μ/kg body weight to hungry rats which were tested over 3 days for their ability to run a complex, 12 choice Warden maze for reward of food. Animals receiving either peptide negotiated the maze significantly (p < 0.01) faster (74.1 and 73.5 vs. 128.8 sec) and made significantly (p < 0.01) fewer errors (5.5 and 5.4 vs. 9.1) than animals receiving the diluent vehicle. These findings did not seem to be explained by differences in appetite, thirst, olfaction, or general activity. Rats injected in a preliminary study with an analog, [D-Phe4]-Met-enkephalin, which has essentially no opiate activity appeared to run the maze as fast as rats injected with [D-Ala2]-Met-enkephalin-NH2 and with just as few errors. Injection of morphine seemed to result in slower running times and more errors in the maze. These results demonstrate that enkephalin and some of its analogs can exert significant behavioral changes after IP administration and that these behavioral effects probably can be dissociated from the opiate effects.
TL;DR: These findings strongly support the concept that pituitary thyrotrophs are regulated by endogenous somatostatin as well as by TRH and thyroid hormones.
Abstract: Passive immunization of rats with an antiserum to synthetic somatostatin caused a 250% elevation of basal serum TSH levels and a nearly 200% increase in TSH-response to TRH. These findings strongly support the concept that pituitary thyrotrophs are regulated by endogenous somatostatin as well as by TRH and thyroid hormones. Serum GH levels in the antiserum-treated rats were considerably higher than those in rats which received normal serum. No clearcut influence on prolactin secretion was observed.
TL;DR: In this paper, a method is described for determining effective renal plasma flow, using the renal counts 1 to 2 minutes after injection and applying background subtraction as a ratio to the total amount of radioactivity injected intravenously with appropriate correction for kidney depth.
TL;DR: Radioactive synthetic α-MSH, prepared by selective tritiation of its dibromo-L-tyrosine2-derivative, was injected into the carotid artery of intact, hypophysectomized or pinealectomized rats, finding large amounts of radioactivity in the pituitary and in the pineal.
TL;DR: The results suggest that the CNS effects observed after systemic administration of enkephalin may involve the dopaminergic receptor mechanism.
TL;DR: The natural opiate methionine-enkephalin and its D-alanine2 analog were iodinated by a method involving lactoperoxidase and purified by partition chromatography on Sephadex G-25 and a modified brain-uptake index (BUI) value of 15 for the tritiated enkphalin indicates that methionines crosses the blood-brain barrier.
TL;DR: This paper examined a variety of relationships between presidential prestige and presidential support in the U.S. House of Representatives and found that the relationship between overall national presidential popularity and overall, domestic, and foreign policy presidential support among various groups of congressmen was weak.
Abstract: Presidential prestige or popularity has often been cited as an important source of presidential influence in Congress. It has not been empirically and systematically demonstrated, however, that such a relationship exists. This study examines a variety of relationships between presidential prestige and presidential support in the U.S. House of Representatives. The relationships between overall national presidential popularity on the one hand and overall, domestic, and foreign policy presidential support in the House as a whole and among various groups of congressmen on the other are generally weak. Consistently strong relationships are found between presidential prestige among Democratic party identifiers and presidential support among Democratic congressmen. Similar relationships are found between presidential prestige among the more partisan Republican party identifiers and the presidential support by Republican congressmen. Explanations for these findings are presented, and the findings are related to broader questions of American politics.
TL;DR: 3H-labeled diisopropylphosphorofluoridate incorporation studies revealed an active-site serine residue in the heavy chain of urokinase.
TL;DR: In this paper, a mathematical model for the unsteady fluid-dynamic response of the semicircular canals is developed, where the endolymph is assumed to be an incompressible Newtonian fluid and the presence and effects of both the utricle and the cupula are specifically accounted for.
Abstract: A mathematical model for the unsteady fluid-dynamic response of the semicircular canals is developed. The endolymph is assumed to be an incompressible Newtonian fluid and the presence and effects of both the utricle and the cupula are specifically accounted for. A first approximate solution is obtained using a singular perturbation method. It is shown that the canal can be modelled as a heavily damped, second-order system which behaves as an angular-velocity meter. A comparison of the model response with experimental results is made; fairly good agreement is found.
TL;DR: The offspring of teenage mothers are at greater risk than the offspring of older women although quality prenatal care and origin in a favorable socioeconomic background will ameliorate substantial elements of this risk.
TL;DR: ACTH/MSH 4-10 improved attention and in so doing improved visual-motor learning and visual, but not verbal, memory, EEG data were consistant with activation of the diffuse thalamic projection system.
Abstract: Twenty normal, male volunteers were administered a subcutaneous injection of either ACTH/MSH 4–10 or diluent and two weeks later received the alternate injection inca complete crossover, double-blind design with order balanced. Subjects were given a battery of psychological tests including a continuous performance task (CPT), following each injection. Visual evoked responses were recorded during the CPT. Resting, eyes-closed EEGs were also obtained. ACTH/MSH 4–10 improved attention and in so doing improved visual-motor learning and visual, but not verbal, memory. EEG data were consistent with activation of the diffuse thalamic projection system.
TL;DR: It was speculated that MSH/ACTH 4-10 may be unquely coded for perceptor/attentional functioning and may be useful as a treatment for disorders of attention.
Abstract: Twenty adult mentally retarded men were randomly assigned to receive MSH/ACTH 4–10 or a vehicle control solution in a double blind procedure. After an intravenous injection the subjects were presentedd with an orienting sequence and a series of behavioral tests. Treatment with the peptide resulted in a significant decelerative heart rate response during the test stimulus of the orienting sequence. Improved performance of the intradimensional and extradimensional shift of a visual discrimination procedure was significant for subjects receiving MSH/ACTH 4–10. The pattern of response on the subproblem analysis of the extradimensional shift reflected greater dimensional attention in the subjects treated with the peptide. Attentive subjects given MSH/ACTH 4–10 evidenced significant improvement on a rhythm matching test, a test of spatial localization and a visual retention test. The data were interpreted as indicating that the peptide resulted in improved attention of stimulus processing. It was speculated that MSH/ACTH 4–10 may be uniquely coded for perceptual/ attentional functioning and may be useful as a treatment for disorders of attention.