Showing papers by "Laval University published in 1973"
TL;DR: An application of enzyme linked immunoassay technique for quantitation of rat AFP by competitive and sandwich procedures, 1 ng AFP/ml can be reproducibly detected with both methods.
101 citations
TL;DR: The effects of dry anaesthetic gases on the tracheobronchial ciliated epithelium were recently described by Chalon, Loew and Malebranche as discussed by the authors, who measured the heat and moisture pattern in the airways during clinical anaesthesia using a non-rebreathing system and compared it with the semiclosed circle and normal patients at rest.
Abstract: TttREE MAJOR DISADVANTACES are currently associated with non-rebreathing systems in anaesthesia. The first is the cost of discarding large amounts of expensive gases and vapours in the ambient atmosphere. The second, closely related to the first, is operating room pollution. 1,2 The third is concerned with the potentially harmful effects of flushing the respiratory tract with desiccated gas mixtures, z,4 We can imagine, in theory, the threatening sequence associated with the inhalation of a dehydrated gas mixture, particularly when the air-conditioning facilities of the nasal passages are being by-passed. It can be assumed that the dry gases will reach the trachea still completely dry, at a temperature very much the same as room temperature. Consequently, the inspired gas mixture will take up moisture and heat from the tracheobronehial tree, leading to local hypothermia, poor ciliary activity, decreased water content of mucus, impaired mucus rheology and accumulation of viscid secretions. This may not be a serious handicap to anyone who can cough forcibly, but for the operative patient, whose power to cough is impaired, it may be disastrous. The effects of dry anaesthetic gases on the tracheobronchial ciliated epithelium were recently described by Chalon, Loew and Malebranche. 5 Having sampled the ciliated epithelium of the tracheobronchial tree from bronchial lavage, they noticed deciliafion, loss of endplates and distortion and pyknosis of the nuclei. However, no measurements of the actual moisture in the tracheobronchial tree were done prior to sampling, so documentation on this aspect still remains very scant. The purpose of our work was to measure the heat and moisture pattern in the airways during clinical anaesthesia using a non-rebreathing system and to compare it with the semiclosed circle and normal patients at rest.
94 citations
TL;DR: The depletion of secretory granules and Golgi hypertrophy observed in the somatotrophs under the influence of N6-monobutyryl-cyclic AMP was not prevented at all by the inhibition of protein synthesis.
90 citations
TL;DR: Although the inhibitory effect of 10-7 to 10-5M vincristine sulfate was usually slight in the first 45-min incubation period, this agent led, during the following 60 min of incubation, to a 50-70% inhibition of the release of growth hormone induced by 1 X 10- 5M PGET, 25 HIM K+ or purified growth hormone-releasing hormone.
Abstract: A 20-65% inhibitory effect of 25 or 50% deuterium oxide on the basal and induced release of both growth hormone and prolactin from anterior pituitaries was already measured in the first 45 min of incubation at 37 C. Hormonal release was measured by densitometry of proteins of the incubation medium separated on polyacrylamide gels and by radioimmunoassay. Incubation up to 3 hr in 50% deuterium oxide did not cause any detectable morphological alteration of the somatotrophs (growth hormone-secreting cells) nor mammotrophs (prolactin-secreting cells), while microtubules in apparent normal number were seen scattered through the cytoplasm of both cell types. Although the inhibitory effect of 10-7 to 10-5M vincristine sulfate was usually slight in the first 45-min incubation period, this agent led, during the following 60 min of incubation, to a 50-70% inhibition of the release of growth hormone induced by 1 X 10-5M PGET, 25 HIM K+ or purified growth hormone-releasing hormone. Basal and cyclic AMP-induced releas...
69 citations
TL;DR: In this article, the role of the stress analysis of a human aortic valve in relation to the design of a prosthetic valve is examined using experimentally determined information to approximate the in situ loading conditions, geometry and material properties.
64 citations
TL;DR: Data indicate that a state of relative fetal T3 deficiency exists in the human as in the sheep, and this deficiency probably is not due to decreased T3 secretion.
Abstract: Serum T3 concentrations are low (<15 ng/100 ml) before 24 weeks and increase progressively thereafter to term, but both T3 and free T3 (FT3) levels are lower than paired maternal concentrations. Moreover, throughout gestation T4/T3 and FT4/FT3 ratios consistently exceed paired maternal ratios. The mean T4/T3 content ratio of fetal thyroid glands (14.3) is similar to that (19.5) of adult glands. These data indicate that a state of relative fetal T3 deficiency exists in the human as in the sheep. This deficiency probably is not due to decreased T3 secretion.
59 citations
TL;DR: In this article, the shear behavior of granular materials at moderately high pressures up to 1600 lb/sq.in. was studied in drained triaxial tests and it was shown that the stress, strain, volume change behavior are primarily governed by particle degradation.
53 citations
TL;DR: The distribution of monoamine (catecholamines and 5‐hydroxytryptamine)‐containing nerve terminals in the brain of the painted turtle was studied by means of the histofluorescence technique.
Abstract: The distribution of monoamine (catecholamines and 5-hydroxytryptamine)-containing nerve terminals in the brain of the painted turtle (Chrysemys picta) was studied by means of the histofluorescence technique of Falck and Hillarp. The highest concentration of monoamine terminals in this reptilian brain occurs within the ventral region of the strio-amygdaloid complex which on this basis may be related to the mammalian neostriatum (caudate nucleus and putamen). Numerous catecholamine type nerve endings are also present in several other regions of the turtle brain, namely: the dorsal cortical layer, the dorsolateral portion of the septum, the habenula, the nuclei dorsomedialis and dorsolateralis of the thalamus, the lateral part and median eminence of the hypothalamus, the tectum and the brain stem reticular formation (more especially its lateral edge). The greatest concentration of 5-hydroxytryptamine (serotonin) type nerve endings is found in the dorsomedial portion of the septum, nucleus geniculatus lateralis, nuclei pretectalis, interpeduncularis and isthmi, the tectum and the reticular formation of the brain stem (more especially its medial portion). These monoamine nerve terminals belong to several groups of neurons whose cell bodies are located in the brain stem and, to a lesser degree, in the hypothalamus of the turtle.
51 citations
TL;DR: In this paper, the authors examined the axial field distribution of a regular axicon when the incident wave is plane and uniform, and when it has a gaussian irradiance distribution.
Abstract: The transmitting axicon is examined for the axial field distribution of a regular axicon when the incident wave is plane and uniform, and when it has a gaussian irradiance distribution. In the microwave region, the focal depth of an axicon does not differ very much from that of a perfect lens. In the visible region, the axicon possesses a much greater focal depth, which can be greatly changed by changing the curvature of the slanting side of the axicon. For an axicon with a straight slanting side and small height, when a gaussian incident wave is used, the irradiance at the principal focus varies inversely with the focal length.
51 citations
01 Aug 1973
TL;DR: In this article, the reduction of metal sulfides by H2 at 800°C was studied and it was shown that copper sulfides and copper-iron sulfides were reduced rapidly to metals.
Abstract: Calcium oxide favors greatly the reduction of metal sulfides by H2 at 800°C. Copper sulfides and copper-iron sulfides are reduced rapidly to metals: Cu2S+H2+CaO→2Cu+CaS+H2O CuS+H2+CaO→Cu+CaS+H2O Cu5FeS4+4H2+4CaO→5Cu+ Fe+4CaS+4H2O
50 citations
TL;DR: High-resolution radioautography reveals that DNA is present within both the dense and lighter portions of the nucleolar loops of Allhim porrum meristematic cells, adding further support to the hypothesis that the convoluted filamentous structures in question correspond to loops of chromosomal origin and are thus related to theucleolar organizer.
Abstract: SUMMARY The interphase nucleolus in Allhim porrum meristematic cells is characterized by the presence of 1-4 dense fibrillar zones of rather complex organization. Each such zone appears to consist essentially of a convoluted, evacuolated, filamentous structure approximately 1-5 /*m in diameter. At the ultrastructural level, these structures exhibit an intricate array of lacunar spaces each of which is surrounded by a dense coating. These lacunae are filled with a loose fibrillar material and the largest ones sometimes also show a dense central core. In appropriate preparations, certain of the peripherally located lacunae are found to be continuous with segments of chromosomes. High-resolution radioautography reveals, moreover, that DNA is present within both the dense and lighter portions of the nucleolar loops. These observations add further support to the hypothesis that the convoluted filamentous structures in question correspond to loops of chromosomal origin and are thus related to the nucleolar organizer.
TL;DR: In this paper, experimental composition maps have been obtained of four H2-air turbulent diffusion flames of varying diameter but constant Reynolds number, and Nitric oxide levels were found to scale with a characteristic “jet time,” modified to include the effects of buoyancy on flame shape.
Abstract: Experimental composition maps have been obtained of four H2-air turbulent diffusion flames of varying diameter but constant Reynolds number. Nitric oxide levels were found to scale with a characteristic “jet time,” modified to include the effects of buoyancy on flame shape. A comparison is made between present measurements, those of Kent and Bilger (1972), and a simple model of NO formation. The results suggest that the rate of NO formation is not predictable on the basis of fluctuating adiabatic equilibrium kinetics but requires consideration of turbulent combustion in detail and possibly the effects of excess radical concentrations.
TL;DR: Simulation results showed that the shortcomings of simple dispatching rules are remedied by using the SPT-T scheduling rule.
Abstract: This paper discusses the development of a scheduling rule and summarizes the results of the evaluation of its performance with respect to some tardiness related criteria. Studies done on job shop scheduling indicated that the simple dispatching rules which mostly perform well with respect to a criterion of performance may have undesirable results with respect to other criteria. In this paper, a scheduling rule with truncation process called SPT-T is introduced and studied. Simulation results showed that the shortcomings of simple dispatching rules are remedied by using the SPT-T scheduling rule.
TL;DR: In this paper, the productivity:biomass (P:R) ratio for phytoplankton was studied using a replicated sampling design at six stations in a small marine basin.
Abstract: The productivity:biomass (P:R) ratio for phytoplankton was studied using a replicated sampling design at six stations in a small marine basin. On six out of ten sampling days, statistically significant differences were revealed in the P:B ratios between stations. This result is consistent with the concept of contemporaneous disequilibrium which emphasizes the spatial component of the heterogeneity of the phytoplankton habitat,
TL;DR: The C9 bodies observed in interphase with this cytological procedure are frequently associated with the nucleolus and this heterochromatin is less compact than previously shown and may represent repetitive DNA with a specific role.
Abstract: Using a specific technique which stains the secondary constriction of number 9 chromosomes in man, we observed that this segment frequently appears to be composed of multiple small units packed together in metaphase as well as in interphase. During prophase of the first meiotic division in man, this segment looks like a diffuse structure, suggesting division and multiplication of these units. On the other hand, the C9 bodies observed in interphase with this cytological procedure are frequently associated with the nucleolus. This heterochromatin is less compact than previously shown and may represent repetitive DNA with a specific role.
TL;DR: Data show membrane phospholipids to be intimately involved in the receptor for thyrotropin-releasing hormone.
TL;DR: In this article, it was shown that level curves of a domain convex in the v-direction bound a domain with the same property, i.e., the intersection of D with each vertical line is connected.
Abstract: Let D be a plane domain which is convex in the v-direction, i.e.t the intersection of D with each vertical line is connected (or empty). It has been an open question whether level curves of a domain convex in the v-direction bound a domain with the same property. In this note we construct an example which settles the question in the negative.Closely related is a family ? of analytic functions g in the unit disk with the property that g(0) = 0 and Re{(1 - z2)g(z)/z} ⋚ 0. For univalent functions we show that membership in ? is essentially characterized by the geometric condition that Im g(ei0)⋚ 0 for a.e. ? ? (0, ?) and Im g(ei0)⋚ 0 for a.e. We conclude with a coefficient theorem
TL;DR: The histochemical detection of glycoproteins in the granules of thyroidectomy cells and the localization of [SH]fucose, which is known to be a terminal sugar, in the side chains of T S H are reported.
Abstract: W h e n the secretion of thyroid hormones is prevented by thyroidectomy or propyhhiouraci l (PTU) t reatment , the anter ior pi tui tary cells secreting the thyroid-st imulat ing hormone (TSH) become enlarged and their rough endoplasmic re t iculum (RER) forms large dilated cisternae (1, 2). These ceils are known as the thyroidectomy cells. The presence of granules in the dilated cisternae is a common finding 3 wk or more after suppression of thyroidal activity (1). These intracisternal granules are thought to be different from the secretory granules observed free in the cytoplasm (1). To our knowledge, little information is available on the composit ion of intracisternal granules. In this pre l iminary study, we report the histochemical detection of glycoproteins in the granules of thyroidectomy cells and the localization of [SH]fucose, which is known to be a terminal sugar (3), in the carbohydra te side chains of T S H (4). M A T E R I A L S A N D M E T H O D S
TL;DR: Observations would be consistent with the view that the various types of extranucleolar bodies are morphological expression - like the puffs of the polytene and the loops or spheroids of the lampbrush chromosomes - of differential gene activity on the part of the localized regions of the chromosomes during oocyte growth.
Abstract: The dictyate nucleus of the growing mouse oocyte exhibits, besides the nucleolus, 3 ultrastructurally distinct types of smaller formed entities referred to as extranucleolar bodies. The extranucleolar bodies of the first type (fibrillogranular bodies) consist of intermingled masses made up of closely arranged convoluted fibrils, 6-10 nm in width, interspersed with electrondense granules approximately 15 nm in diameter. The extranucleolar bodies of the second type (fibrillar bodies) are composed of an entanglement of loosely arranged convoluted fibrils 4-10 nm in diameter; such bodies are also characterized by the presence within their mass of irregularly shaped widely scattered islands of varying sizes made up of densely packed fibrillar material exhibiting a somewhat greater electron opacity. The extranucleolar bodies of the third type (coiled bodies) appear to consist of an aggregate of highly contorted threads, the thickness of which varies from 20 to 35 nm; the threads themselves are composed of bundles of fibrils 5 nm thick which are irregularly twisted along their axis. An attempt is made to interpret these morphological findings in the light of current knowledge concerning the architectural and functional organization of the oocyte nucleus in general during the protracted dictyate stage of meiotic prophase. Our observations would be consistent with the view that the various types of extranucleolar bodies are morphological expression - like the puffs of the polytene and the loops or spheroids of the lampbrush chromosomes - of differential gene activity on the part of the localized regions of the chromosomes during oocyte growth.
TL;DR: The discussion bears on the intracellular concentrations of the osmolytes studied, as influenced by the variations in cell water content and on the role played by potassium, TMAO and free amino acids in the isosmotic intrace cellular regulation of the hagfish and other animals.
TL;DR: The occurrence of a three-dimensional microfilamentous network in the nerve cell processes led us to hypothesize that it plays a role in translocation of materials.
Abstract: After the staining of nervous tissue with phosphotungstic acid in absolute ethanol (E-PTA), a selective opacification occurs at certain specific sites, while other structures, especially the plasma and intra-cellular membranes, remain electron-lucent. Among those selectively stained sites, our studies have been focussed on: (1) The dense synaptic material consisting of several presynaptic clumps, termed projections, an intrasynaptic dense line and a subsynaptic web from which fine fibrillar wisps extend into the surrounding ground substance; (2) Neurofilaments and neurotubules, the surface of which is bristled by numerous side-arms; (3) A microfilamentous network intertwines the neurotubules, the neurofilaments and the mitochondria in the dendrites and axon, and is also connected to the E-PTA dense undercoating delineating the inner aspect of the plasma membrane and to the fine wisps emanating from the subsynaptic web. A three-dimensional microfilamentous latticework is thus formed in the nerve cell processes; (4) Dense cytoplasmic inclusions, termed nematosomes, which are usually located in the ground substance of the perikaryon among or in the vicinity of clusters of ribosomes. Tiny microfilaments emanate from the peripheral strands of these bodies. The presence of basic residues in the chains of structural proteins of which consist the subsynaptic web and the nematosome is plausible, since the specificity of the E-PTA staining procedure for the detection of basic residues has previously been put forth. The occurrence of a three-dimensional microfilamentous network in the nerve cell processes led us to hypothesize that it plays a role in translocation of materials. It may provide the motive force for the axoplasmic transport, for instance, with the neurotubules, as well as, plausibly, with the neurofilaments, serving as attachment sites and guideways.
TL;DR: Direct recording of interneurons interposed in feed-back and feed-forward inhibitory pathways is attempted to study their behavior during natural sleep and waking in freely moving animals.
TL;DR: The administration of 3-hydroxy-3-methylglutaric acid to cholesterol-fed rabbits significantly depressed the levels of serum cholesterol, phospholipids, triglycerides, free fatty acids and total lipids and significantly regressed the pre-established atheroma in white rabbits.
TL;DR: An inexpensive automated fluorometric technique for blood galactose determination has been modified to use dried blood spots available through phenylketonuria screening programs, which is more efficient than the currentenzymatic method.
Abstract: An inexpensive automated fluorometric technique for blood galactose determination has been modified to use dried blood spots available through phenylketonuria screening programs. The method is more efficient because of its high capacity (≃85,000 tests a year), low cost (≃$3,000 a year in reagents), and high specificity (enzymatic method).
TL;DR: It is shown that the stimulus for increasing the concentration of free amino acids is mainly the osmolality of the medium, and the free amino acid pool plays an active role in intracellular osmotic regulation.
TL;DR: Preliminary studies indicate that nine viruses will replicate in both epithelial-like and fibroblast-like cells, and the persistence of species specificity by fluorescence is found.
Abstract: A cell line has been derived from the inner lining of the pig oviduct. During 33 months in continous culture, the cells have been subcutured 145 times. Early passage cells had an epithelial-like morphology with clear and abundant cytoplasm. A spontaneous morphological alteration occurred at the 50th subculture by emergence of fibroblast-like cells. Evolution towards establishment of a cell line was suggested by the spontaneous morphological alteration, increase of the maximum population density without a significant change in the diploid state (92nd subculture), increase, in size and number of nucleoli, and increase in the nuclear-cytoplasmic ratio and of cytoplasmic basophilia. Evidence of pig origins is subtantiated by the karyotype (38, XX), the persistence of Barr bodies indicating female origin (140th subculture) and the persistence of species specificity by fluorescence (141th subculture). Preliminary studies indicate that nine viruses will replicate in both epithelial-like and fibroblast-like cells.
TL;DR: In this article, the Van de Graaff accelerator was used to study neon in the extreme ultra-violet region using doubly-ionized beams, and the authors observed many transitions from 50 A to 150 A belonging to highly-stripped neon.
TL;DR: In this paper, the experimental conditions and requirements for the continuity equation to reduce to a total differential equation are analyzed, and a simple method for obtaining rate coefficients from pulsed microcatalytic reactors, provided that the conversions are limited to differential conversions.
TL;DR: In this article, a generalization of minimum bias estimation was developed and applied to a setting in which the true model is assumed to be the ratio of real polynomials (rational function) while the approximating equation is a polynomial of low order.
Abstract: A generalization of minimum bias estimation as introduced in [6] is developed and applied to a setting in which the true model is assumed to be the ratio of real polynomials (rational function) while the approximating equation is assumed to be a polynomial of low order.
TL;DR: In this article, the short-term stability of the Rb87 maser was investigated as a function of the maser power output and of the receiver cutoff frequency, and the experimental data were compared to theoretical results obtained from an approximate theory.
Abstract: Measurements of the short-term stability of the Rb87 maser are reported here. The measurements were made as a function of the maser power output and of the receiver cutoff frequency. The experimental data are compared to theoretical results obtained from an approximate theory. In this theory the transfer function of the maser for thermal noise is derived, and the spectral density of the phase fluctuations is calculated. An analytical expression for the "Allan variance" is also given. A comparison of the stability of the Rb87 maser with existing frequency standards shows its superiority for averaging times less than 1 s. We obtain ?f/f ? 1.3 × 10-3 ?-1. A stability of 5 × 10-12 for ? ?1000 s is also reported.