Showing papers by "Tulane University published in 1969"
1,226 citations
TL;DR: This formulation of structure represents the elucidation of the first of the hypothalamic hormones that have been sought for so long and is chemically based on the chromatographic identity in seventeen diversified systems and biologically based on a quantitative comparison of the hormonal activities of the natural and synthetic products.
495 citations
470 citations
TL;DR: In this paper, a study was conducted to empirically test the theory of commitment developed by Howard Becker, who argued that commitment occurs through a process of placing side-bets.
Abstract: T \his is a report of a study designed to empirically test a theory of commitment developed by Howard Becker.1 Becker contends that commitment occurs through a process of placing side-bets. When an individual has made a side-bet, he has "staked something of value to him, something originally unrelated to his present line of activity."2 In general, Becker contends that the greater the number of side-bets, the greater the commitment of the individual. Two types of commitment were examined in this study: commitment to the organization and commitment to the occupation. Specifical-ly, this study focused on personnel managers. The amount of commitment of personnel managers was ascertained by a series of questions which attempted to determine for what reasons, if any, a person would leave his organization and his occupation. Such an approach was suggested by Becker:
303 citations
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01 Jan 1969215 citations
TL;DR: Development of the herpes-type virus of the frog kidney tumor was investigated by electron microscopy and high-resolution autoradiography in eyechamber transplants of tumor maintained at 7.5 C for up to 27 weeks.
Abstract: Development of the herpes-type virus of the frog kidney tumor was investigated by electron microscopy and high-resolution autoradiography in eyechamber transplants of tumor maintained at 7.5 C for up to 27 weeks. Virus particles were first detected at 10 weeks in nuclei containing aggregates of dense granular material. The initial incorporation of a pulse of (3)H-thymidine into these aggregates indicated that they contained newly synthesized viral deoxyribonucleic acid. Capsids enclosing doubleshelled cores were labeled with (3)H-thymidine before capsids with dense cores, and intermediate core forms were observed, suggesting that the double-shelled core transforms into the dense core. Particles with dense cores were observed while being enveloped by budding through the inner membrane of the nuclear envelope, and subsequently while being unenveloped in passing through the outer membrane into the cytoplasm. Virus particles within the cytoplasm acquired fibrillar coats and budded into vesicles, from which they were released, in enveloped form, at the cell surface. Tubular forms and particles considerably smaller than virus particles were regularly encountered in infected nuclei, and the relationship of these forms to virus replication is discussed.
187 citations
TL;DR: Biological activity of thyrotropin-releasing hormone was abolished by diazotized sulfanilic acid, N-bromosuccinimide, or acid hydrolysis, but was not affected by periodate or by incubation with proteolytic enzymes.
155 citations
TL;DR: Renal tumors were produced by injection of a cell fraction of a tumor into triploid tadpoles of Rana pipiens before they began feeding and implanted nuclei were transplanted into activated and enucleated eggs.
Abstract: Renal tumors were produced by injection of a cell fraction of a tumor into triploid tadpoles of Rana pipiens before they began feeding. Triploid tumor cells were dissociated and transplanted into activated and enucleated eggs. Pluripotency of the implanted nuclei was evidenced by the formation of swimming triploid tadpoles.
152 citations
TL;DR: Histochemical and electron microscopic studies of the heart of a patient with Fabry's disease revealed the presence of extensive glycolipid deposits in the cardiac muscle fibers, vascular smooth muscle, endothelium and connective tissue cells of the mitral valve.
Abstract: Histochemical and electron microscopic studies of the heart of a patient with Fabry's disease (angiokeratoma corporis diffusum universale) revealed the presence of extensive glycolipid deposits in the cardiac muscle fibers, vascular smooth muscle, endothelium and connective tissue cells of the mitral valve. These deposits formed lamellae arranged either concentrically or in parallel stacks; the lamellae were often enclosed by limiting membranes and showed a periodic spacing of 40 to 45 A. The cardiovascular manifestations of Fabry's disease, which consist of cardiac hypertrophy and dilatation, congestive heart failure, anginal chest pain, myocardial infarction and hypertensive heart disease, are reviewed in detail. The association of this disorder with valvular heart disease is discussed.
129 citations
128 citations
TL;DR: Treatment with erythromycin appears to be the most effective of the 3 drugs studied in prophylaxis against pertussis in exposed susceptible individuals, and in aborting or attenuating the illness when given to patients in the early preparoxysmal stage of the disease.
TL;DR: The present studies of the histochemical and electron microscopical changes induced in the heart muscle by overdoses of isoproterenol, epinephrine, and norepinephrine were undertaken in the hope of providing a better understanding of the responses of myocardium to various types of injury.
Abstract: The histopathology of myocardial lesions produced by large doses of sympathomimetic amines has been the subject of detailed study in recent years.'-' Few reports are available, however, on the histochemical and electron microscopical features of such lesion^.^-^ * The present studies of the histochemical and electron microscopical changes induced in the heart muscle by overdoses of isoproterenol, epinephrine, and norepinephrine were undertaken in the hope of providing a better understanding of the responses of myocardium to various types of injury.
TL;DR: Systematic evaluation was made of the differential effects of pie- and/or early postnatal TP on the somatic structures and male behavior capacity of intact and spayed female rats, finding that depending on the type of treatment, varying amounts of somatic modification resulted.
TL;DR: Cette étude indique que l'administration de α MSH aux rats les fait retenir une tâche appétitive d'un effet sur the persévération ou la mémoire.
Abstract: Cette etude indique que l'administration de α MSH aux rats les fait retenir une tâche appetitive. Un effet sur la perseveration ou la memoire est implique.
TL;DR: It is suggested that atrial muscle cells may have a secretory as well as a contractile function.
Abstract: A study was made of the ultrastructural and histochemical characteristics of atrial muscle cells. The myofibrils of these cells do not converge at the nuclear poles as in the ventricular cells, but leave large sarcoplasmic spaces in the central cores, which contain mitochondria, small amounts of rough-surfaced sarcoplasmic reticulum, free ribosomes and one or more well developed Golgi complexes. Numerous cytoplasmic granules, many of which are closely associated with the Golgi material, are present in these cells. These granules can be demonstrated in paraffin sections by the Bowie stain. The smooth-surfaced sarcoplasmic reticulum of atrial fibers consists of a meshwork of interconnected tubules which pass uninterruptedly from one sarcomere to another. No transverse dilatations or T tubules are present as in ventricular cells; however, there are numerous subsarcolemmal cisterns consisting of flattened dilatations of sarcoplasmic reticulum which lie in close proximity to the internal surface of the sarcolemma. There is considerable variation from one cell to another in the number and compactness of arrangement of the myofibrils, and in the abundance of other cellular components.
On the basis of the above findings, we suggest that atrial muscle cells may have a secretory as well as a contractile function.
TL;DR: A lattice ordered group is called complete if each set of elements that is bounded above has a least upper bound (and dually) as mentioned in this paper, and each archimedean l-group has a completion in the sense of the following theorem.
Abstract: A lattice ordered group(‘l-group’) is called complete if each set of elements that is bounded above has a least upper bound (and dually). A complete l-group is archimedean and hence abelian, and each archimedean l-group has a completion in the sense of the following theorem.
TL;DR: An interaction of the effects of treatments on MSH release was observed with morphine and Morphine, and the tendency for Nembutal to cause a lowering of plasma MSH activity without much change in pituitary MSH content was not statistically significant.
Abstract: Plasma and pituitary MSH activities were measured in albino rats after various treatments. Administration of trifluoperazine increased plasma MSH activity and decreased pituitary MSH activity. Ether also elevated plasma MSH levels and lowered pituitary MSH content 2 min after anesthesia; however, plasma MSH activity in these rats exposed to ether vapors subsequently declined despite a persistent decrease in pituitary MSH levels. Pretreatment with dexamethasone failed to block the MSH releasing effects of ether at 2 min. MSH also appeared to be released by synthetic lysine vasopressin. Darkness diminished and pinealectomy elevated pituitary MSH content but did not seem to affect plasma MSH levels. The tendency for Nembutal to cause a lowering of plasma MSH activity without much change inpituitary MSH content was not statistically significant. Morphine raised plasma MSH levels but did not alter pituitary MSH levels. An interaction of the effects of treatments on MSH release was observed with morphine and et...
TL;DR: The results are best explained by the presence of an enzyme in the plasma and various tissues which is capable of inactivating TRH, which is proportional to the enzyme concentration and time.
Abstract: SummaryInactivation of porcine thyrotropin-releasing hormone (TRH) by plasma fractions in vitro was determined using mice maintained on a low iodine diet and pre-treated with 5 μCi of 125I and 0.085 μg of triiodothyronine. Incubation of TRH with porcine, bovine, or human serum caused a complete inactivation in 30 min. The optimum pH for the inactivation was about 7 and the optimal temperature was between 30 and 40°. The rate of inactivation of TRH was proportional to the enzyme concentration and time. Preheating rat plasma to 56° for 30 min greatly reduced this inactivation. When plasma fractions of porcine, bovine, and human origin were incubated with TRH in Krebs-Ringer bicarbonate, pH 7.4, at 37° for 30 min, alpha, beta, and gamma globulin fractions caused an 80-90% inactivation of added TRH. Albumin and fibrinogen caused a 40-50% reduction in TRH activity while the beta-lipoprotein fraction only induced a slight inactivation of TRH. Incubation of TRH with slices of rat liver, kidney, brain cortex, and...
TL;DR: The findings reported here appear to be unrelated to the reported effects of amino acid supply on liver polysome profiles, and insulin, in concert with glucose, has a rapid effect on the liver resulting in changes in the polysome profile.
TL;DR: The potentially grave prognosis in patients with this rhythm disturbance is underscored by the fact that 16 of the 31 patients (52 per cent) died during the hospital stay in which the arrhythmia occurred and that 9 of these died within 45 days of its onset.
TL;DR: The arterial vasculature of the papillary muscles of the left ventricle was studied in detail in ten human hearts, using the technique of stereoscopic arteriography followed by detailed histologic examination.
TL;DR: Previous reliable reports, and Hall5 has summarized data and discussed several aspects of the use of natural objects as tools by several groups of animals.
Abstract: Goodall1–3 and Suzuki4 have reported seeing wild chimpanzees use objects as tools to obtain food. Goodall has also summarized previous reliable reports, and Hall5 has summarized data and discussed several aspects of the use of natural objects as tools by several groups of animals.
TL;DR: The mouse virulence of two K antigen-containing (L variety) strains of Escherichia coli isolated from human septicemia, and of their variants which lacked K antigen, was studied.
Abstract: The mouse virulence of two K antigen-containing (L variety) strains of Escherichia coli (serotype O2:K1) isolated from human septicemia, and of their variants which lacked K antigen, was studied. The strains containing envelope antigen (K+) were highly virulent when injected intracerebrally or when suspended in mucin and injected intraperitoneally. After intraperitoneal injection of E-107 K+ (but not K-), there was a marked initial growth in the peritoneal cavity followed by bacteremia and infection of all the organs examined. In the mucin-enhanced lethal infection, this growth continued until death of the animal; in the nonlethal infection, growth ceased and the count dropped quickly after approximately 5 hr. Host defenses were depressed greatly by intraperitoneally, but not intravenously, administered mucin. Bacteria were most virulent when injected intraperitoneally. In vitro phagocytosis of the K+ bacteria required opsonins not needed for phagocytosis of the smooth K- variants. Opsonins were found in immunized rabbit and normal mouse sera. Immune rabbit sera contained antibodies with anti-K specificity which were opsonic in vitro and highly protective in vivo when administered passively. There appears to be a lesser anti-O opsonic and protective activity involving one of the strains (E-107 K+), and colonial morphology, agglutination, and absorption tests indicated a low amount of K antigen on this organism. No anti-O opsonic or protective activity could be shown involving the other strain (E-102 K+). When standard serological typing procedures were used, these two strains appeared to be identical serologically, but they differed greatly in sensitivity to immune rabbit serum in phagocytosis experiments in vitro.
TL;DR: Injection of frog embryos with a zonal centrifuge purified fraction of herpes-type virus (prepared from virus-containing Luck� tumors) resulted in a high incidence of kidney tumors, which suggests that this form of the virus plays a role in the genesis of the Luck� tumor.
Abstract: Injection of frog embryos (Rana pipiens) with a zonal centrifuge purified fraction of herpes-type virus (prepared from virus-containing Lucke tumors) resulted in a high incidence of kidney tumors. This partially purified oncogenic fraction contained a high concentration of an enveloped form of the frog herpes-type virus (adjacent fractions lacked this particle and were not oncogenic), which suggests that this form of the virus plays a role in the genesis of the Lucke tumor.
TL;DR: Twenty-eight neonates whose Apgar scores did not improve during 5 minutes of standard resuscitation were placed in cold water and artificially respired, and cooling these infants increased the Apgar Scores, even for those with a 0 rating.
TL;DR: Evidence presented here indicates that final release is by microbubbles from the secretory epithelium, which would explain Wittenbergs observations that the gases found in swim bladders have ratios more closely related to their solubility coefficients in water than to ambient partial pressures.
Abstract: The Haldane-Koch-Scholander-Kuhn-Steen theory of salting out countercurrent multiplication effect of the rete mirabile now accounts for release of most gases in the fish swim bladder. Evidence presented here indicates that final release is by microbubbles from the secretory epithelium. There is only one specific cell type in a highly vascularized epithelium. It is characterized by complex folds in the paravascular zone and by “gas” forming bodies which seem to form from plentiful Golgi material. The bodies are formed with dark amorphous matrix that becomes patterned (tubular or lamellar), finally froths and then is released to the gas surface. Residual material may form myelin-like layers on the lumenal surface. Active cells are also characterized by surface villi and subsurface, parallel cisternal spaces. Gas may be formed by cells not touching the gas surface and released through intercellular spaces. There are discontinuous desmosomes (maculae adhaerentes) near the gas surface and there are no tight junctions (zonulae occludentes). Gas release as bubbles would explain Wittenbergs observations that the gases found in swim bladders have ratios more closely related to their solubility coefficients in water than to ambient partial pressures. A surfactant may be present to lower the surface tension of the microbubbles. The carrier in the cytoplasm would have to be an iron-protein (or perhaps peroxidase) compound capable of binding molecular oxygen.
TL;DR: Evidence was found that Gambusia affinis and Fundulus olivaceus respond to skin extract from their own species with a reaction that may be comparable to the fright reaction known in the Ostariophysi and Gonorynchiformes.
Abstract: Alarm substances and fright reactions were found in three species of Cyprinidae from the southeastern United States (Notropis venustus, N. texanus and Hybopsis aestivalis). Three types of fright reactions were observed corresponding to the vertical distribution of the test species in the natural habitat (top-water, mid-water and bottom). Evidence was found that Gambusia affinis and Fundulus olivaceus (Poeciliidae and Cyprinodontidae) respond to skin extract from their own species with a reaction that may be comparable to the fright reaction known in the Ostariophysi and Gonorynchiformes. A predator odor capable of eliciting a fright response in local prey species was found in three North American predatory fishes \[Lepomis macrochirus, and Micropterus punctulatus (Centrarchidae); Esox niger (Esocidae)\] and in two South American fishes, Astronotus ocellatus and Cichlasoma severum (Cichlidae). The reactions to predator odor by the prey were similar in appearance to those observed in experiments us...