Showing papers by "University of Saskatchewan published in 1980"
TL;DR: Seven families with X-linked mental retardation (MR) have been studied clinically and cytogenetically and all affected males in six of the families were found to have a fragile site on Xq in a number of their peripheral lymphocytes.
Abstract: Seven families with X-linked mental retardation (MR) have been studied clinically and cytogenetically. All affected males in six of the families were found to have a fragile site on Xq in a number of their peripheral lymphocytes. The fragile site was not seen in any of the affected males in the seventh family. The affected males in the six families with the fragile X had a syndrome characterized by a variable degree of MR, macro-orchidism, a characteristic repetitive, jocular speech, normal body proportions, and large jaws and ears. The fragile X chromosome could only be detected in a proportion of female carriers and its frequency in females was found to be correlated with their mental status to be inversely correlated with their age.
196 citations
TL;DR: The authors assesses the apparent effects on job attitudes and organizational performance of recent conversions to employee ownership at three firms and find that favorable effects were most evident at the firm with the largest turnover.
Abstract: This paper assesses the apparent effects on job attitudes and organizational performance of recent conversions to employee ownership at three firms Favorable effects were most evident at the firm
151 citations
TL;DR: The uptake processes of synaptosomal preparations show that accumulation of adenosine into neuronal (and possibly glial) elements may play a major role in regulating the extracellularAdenosine concentration.
Abstract: Uptake of adenosine, a putative inhibitory transmitter or modulator, was investigated in rat cerebral cortical synaptosomes. The accumulation of [3H] adenosine into synaptosomes, using an adenosine concentration of 10 microM, was linear for 30 min at 30 degrees C. The uptake appeared to be mediated by kinetically saturable processes with apparent Km's of 1 microM ("high-affinity A") and 5 microM ("high-affinity B"), both of which were partially sensitive to the presence of external sodium and calcium ions. Both uptake processes were partially inhibited by 2,4-dinitrophenol, implying the presence of active uptake and diffusional components. A study of the metabolites of adenosine taken up by the two uptake systems indicates that the major metabolites were adenosine and nucleotides. However, adenosine incorporated by the high-affinity A uptake system is more likely to form deaminated metabolites, such as hypoxanthine and inosine, indicating a possible functional difference between the two uptake processes. A detailed comparison of the inhibitory properties of certain adenosine analogues and other pharmacological agents has revealed differences between the two adenosine uptake systems. Since the glial contamination in synaptosomal preparations is well established, one of the uptake systems we observed in the present study might be of glial origin. This notion is supported by the findings that the Km values and kinetic properties of papaverine action in he synaptosomal high-affinity A uptake system are similar to those of astrocytes reported in the literature. In conclusion, the uptake processes of synaptosomal preparations show that accumulation of adenosine into neuronal (and possibly glial) elements may play a major role in regulating the extracellular adenosine concentration. Uptake inhibitors, such as diazepam, may exert, at least in part, their pharmacological actions by interfering with the regulation of extracellular adenosine concentrations.
130 citations
TL;DR: In this paper, a stability index based on the probabilistic nature of the transmission system is developed and examined for sensitivity to selected system parameters, which is used for transient stability evaluation.
Abstract: Transient stability evaluation is normally done using fixed system criteria. A particular generation-load- transmission system is subjected to a predetermined perturbation, usually a single phase or three phase fault and the resulting response evaluated. This paper illustrates the inclusion of probabilistic considerations into the transient stability evaluation problem by application to a simple system. A stability index based upon the probabilistic nature of the system is developed and examined for sensitivity to selected system parameters.
124 citations
TL;DR: A fast and efficient method for analysing ionospheric drift records employing the concepts of full correlation analysis ( Briggs et al., 1950) is described in this paper, where only the most accurately determined experimental data, viz. the width of the mean auto correlogram, and the positions and magnitudes of the maxima in the cross correlograms are required.
124 citations
113 citations
TL;DR: In this article, a break in an oil pipeline in mid-winter caused oil to travel underground over a distance of about 850 m. Oil contamination and damage to the soil structure due to the clean-up efforts caused serious yield decreases during the next summer.
108 citations
TL;DR: Both simple decompression and anterior transposition result in improvement in 82% of the cases; however, a higher percentage of full recovery was seen in the cases treated bysimple decompression, which is explained by the facts that the nerve is not handled and its vital blood supply is left intact.
Abstract: The authors report 235 cases of ulnar neuropathy at the elbow. The treatment was simple decompression in 115 cases and anterior transposition in 120 cases. Men were affected 3 times as often as women. The average age of presentation was 54.5 years. The nondominant arm was involved more frequently. The etiology of ulnar neuropathy was diverse, but one-third of the cases fell into the idiopathic category. Numbness and paresthesia were the most common complaints. Examination revealed hypalgesia of the little finger and the medial half of the ring finger, with weakness and wasting of the intrinsic muscles of the hand. Electromyography and nerve conduction studies are important for early diagnosis. Young men with a symptom duration of 1 year or less have a better chance of improvement after the operation. Both simple decompression and anterior transposition result in improvement in 82% of the cases; however, a higher percentage of full recovery was seen in the cases treated by simple decompression. This is explained by the facts that the nerve is not handled and its vital blood supply is left intact.
107 citations
104 citations
TL;DR: The results of the present investigation were related to changes in dopamine and acetylcholine neurotransmission following long-term amphetamine treatement.
Abstract: The effects of long-term amphetamine treatment were examined on self-stimulation responding from the substantia nigra. Rates of self-stimulation responding were substantially depressed among rats chronically treated with amphetamine and tested in the absence of the drug. When rats were subsequently retested after a two day hiatus in which they received imipramine or amitriptyline, the post-amphetamine depression of rates of self-stimulation responding was mitigated. The efficacy of imipramine and amitriptyline in reversing the post-amphetamine depression of self-stimulation responding was also evident during a continuation of the drug (imipramine or amitriptyline)/test sequence, for seven test sessions. The results of the present investigation were related to changes in dopamine and acetylcholine neurotransmission following long-term amphetamine treatement.
TL;DR: In this article, a single crystal α-quartz at ca. 25 K, which had been X-irradiated, has revealed the presence of two new trapped-hole impurity centers.
TL;DR: The results support the proposal that benzodiazepines may exert their pharmacological actions by preventing adenosine uptake, thus enhancing the levels of extracellularadenosine.
Abstract: 1 Diazepam administered intraperitoneally (0.25 mg/kg) enhanced the rate of efflux of [3H]-adenosine and its metabolites from rat cerebral cortex. At a lower dose (0.05 mg/kg), this effect could be detected in only one of four rats. 2 Diazepam (0.05 and 0.25 mg/kg i.p.) depressed acetylcholine release from the rat cerebral cortex. Its effect was reversed by theophylline. 3 Theophylline (15 and 30 mg/kg) enhanced acetylcholine release from the rat cerebral cortex. Diazepam (0.25 mg/kg) administered after theophylline failed to cause a reduction in the rate of release, rather there appeared to be a further enhancement of release. 4 Pentobarbitone sodium (5, 10 and 15 mg/kg i.p.) did not elicit any increase in adenosine release. 5 These results support the proposal that benzodiazepines may exert their pharmacological actions by preventing adenosine uptake, thus enhancing the levels of extracellular adenosine.
TL;DR: A likely involvement of-SH groups in the opposing effects of Mg2+ and guanine nucleotides (GTP) on cardiac muscarinic receptor-agonist interaction is indicated.
Abstract: 1.
The binding of agonist (carbachol) and antagonist (atropine) to the rat heart atrial muscarinic cholinergic receptor sites was investigated.
2.
Divalent cations (Mg2+ or Ca2+), in low concentrations, modestly increased the agonist binding affinity of the receptor site without any effect on the antagonist binding affinity. 3. Guanine nucleotides (e. g. GTP), on the other hand, decreased the agonist binding affinity (but not the antagonist binding affinity), and the extent of GTP effect depended on the absence or presence of divalent cation (Mg2+) in the binding assay. 4. Pretreatment of atrial membranes with N-ethylmaleimide (NEM) altered the agonist binding curve (obtained with varying concentrations of carbachol) such that the Hill coefficient (nH) became very close to 1.0, whereas the corresponding nH values for control (untreated) or dithiothreitol (DTT)-treated membranes were much less than 1.0; NEM or DTT treatments failed to show any effect of antagonist binding curve. 5. NEM treatment abolished both divalent cation-induced and guanine nucleotide-induced alterations in the agonist binding affinity of the receptor site. 6. Monovalent cations in low concentrations did not mimic the effects of Mg2+ or Ca2+ on agonist binding. Instead, concentration dependent decreases in both agonist and antagonist binding affinities and abilities were observed. Neither NEM nor DTT treatments failed to alter the monovalent cation effects on carbachol and atropine binding. 7. These observations indicate a likely involvement of-SH groups in the opposing effects of Mg2+ and guanine nucleotides (GTP) on cardiac muscarinic receptor-agonist interaction. The results further suggest some subtle in vitro differences in the brain and heart muscarinic receptor sites with regard to the influence by divalent cations and guanine nucleotides on the receptor-agonist interaction.
TL;DR: Cross-sectional data from 155 children showed that vocalization disrupted right-hand tapping more than left- hand tapping, and that the degree of asymmetry did not vary with age, which support the developmental invariance hypothesis of language lateralization.
TL;DR: This chapter examines the major applications of plant protoplasts to the study of plant cells and places emphasis on structural studies of higher plant protoplasts especially by electron microscopic methods.
Abstract: Publisher Summary Plant cells are surrounded by a complex cell wall composed primarily of polysaccharides. Techniques have been developed for the routine removal of this wall from a wide range of plant cells. The resulting naked cells or protoplasts provide a unique experimental system that is proving very useful for studying the structure and function of plant cells. Many manipulations that are not possible with intact plant cells are feasible with protoplasts. These include surface labeling of the plasma membrane, complete cell wall regeneration, and cell fusion. Protoplasts are particularly important for examining the plant plasma membrane, a component of the plant cell that is normally inaccessible because of the presence of a cell wall. This chapter examines the major applications of plant protoplasts to the study of plant cells. Emphasis is placed on structural studies of higher plant protoplasts especially by electron microscopic methods. Protoplasts are isolated from a wide variety of plant species and when cultured have produced callus and in some cases complete plants. This chapter presents several examples of plants that have been regenerated from protoplasts.
TL;DR: The intramuscular administration of L‐cycloserine, gabaculine, and aminooxyacetic acid caused significant, time‐dependent increases in the γ‐aminobutyric acid (GABA) content of both whole brain and synaptosomalenriched preparations obtained from the tissue, a linear relationship being observed between the two parameters.
Abstract: The intramuscular administration of L-cycloserine, gabaculine, and aminooxyacetic acid caused significant, time-dependent increases in the gamma-aminobutyric acid (GABA) content of both whole brain and synaptosomal-enriched preparations obtained from the tissue, a linear relationship being observed between the two parameters. In contrast, the administration of hydrazine resulted in a large increase in whole brain GABA level, with little change in the synaptosomal GABA content. The key factor in these different responses appeared to be the degree of inhibition of glutamic acid decarboxylase by the drugs. Pretreatment of mice with the GABA-elevating agents resulted in a delay in the onset of seizures, which was related directly to the increase in synaptosomal GABA content. Although the seizures were delayed, they occurred while the GABA content of nerve endings (synaptosomes) was above that in preparations from untreated animals. The decrease in GABA content at the onset of seizures, expressed as a percentage of the level at the time of injection of the convulsant agent, was, however, reasonably constant. A hypothesis to explain these results is proposed.
TL;DR: It is, therefore, not likely that a net flow of glutamine takes place from astrocytes to neurons, compensating for the loss of TCA constituents when glutamate and GABA are released.
TL;DR: A clear difference between the response of DI-6 and NR1 cells to chlorate even in the absence of nitrate lends support to the observations by others that chlorate inhibits cells by a mechanism other than, or in addition to, its nitrate reductase-catalyzed conversion to chlorite.
Abstract: A comparative study has been carried out of the growth of two lines of Datura innoxia (Mill.) cells, designated DI-6 and NR1, their resistance to chlorate, and their ability to assimilate nitrate in sterile culture. The NR1 cell line was isolated from DI-6 cultures by first growing the latter in a nitrate-based medium for 5 days and then transferring the cells to a medium containing 2 grams liter −1 of casein hydrolysate as the sole N source and 49 millimolar KClO 3 for a 6-week incubation period. Cells which survived the chlorate treatment then were transferred to casein hydrolysate medium and have been cultured in the absence of chlorate for more than 18 months (NR1). DI-6 cells can grow in a nitrate-based medium, whereas NR1 cells can take up nitrate but cannot use it as a N source. The inability of NR1 to assimilate nitrate appears to be due to the lack of an active nitrate reductase in these cells. Through the use of a variety of electron donors and acceptors, the lack of nitrate reductase activity in NR1 cells was shown to be due to the absence of, or a defect in, that component of the enzyme which mediates the reduction of nitrate to nitrite. In other experiments, DI-6 and NR1 were grown on a solid medium containing casein hydrolysate (2 grams liter −1 ) as the sole N source. Under these culture conditions, neither cell line contained an active nitrate reductase. The growth on this medium was compared to that on the same medium containing chlorate at concentrations from 0 to 100 millimolar. DI-6 culture growth was inhibited by 70% at a chlorate concentration of 30 micromolar, whereas growth of NR1 was stimulated by more than 60% on the same medium and by 100% at a chlorate concentration of 30 millimolar. In the presence of 100 millimolar chlorate, the growth of both cell lines was completely inhibited. This clear difference between the response of DI-6 and NR1 cells to chlorate even in the absence of nitrate lends support to the observations by others that chlorate inhibits cells by a mechanism other than, or in addition to, its nitrate reductase-catalyzed conversion to chlorite. Nitrite reductase was induced by nitrate in NR1 cells as well as in DI-6. This observation is a further confirmation of the fact that nitrate, not nitrite, is the true inducer of the nitrate assimilatory pathway in higher plants.
TL;DR: The results were attributed to changes in dopamine neurotransmission following prolonged exposure to amphetamine and were discussed in terms of an animal model for ‘amphetamine psychosis’ and ‘postamphetamine depression’ in man.
Abstract: The effects of long-term amphetamine treatment were evaluated on responding supported by self-stimulation of the substantia nigra. Rats repeatedly treated with d-amphetamine, and tested with a low dose of the drug that ordinarily has no behavioral effect, showed higher response rates than animals repeatedly treated with saline and tested with the same dose of amphetamine. In contrast, a depression in responding was observed among animals that received long-term amphetamine administration and were tested with saline. The effects of long-term amphetamine treatment on self-stimulation could not be explained by the intrusion of drug-induced competitive behaviors such as locomotor activity and stereotypy. The results were attributed to changes in dopamine neurotransmission following prolonged exposure to amphetamine and were also discussed in terms of an animal model for ‘amphetamine psychosis’ and ‘postamphetamine depression’ in man.
TL;DR: Ghosts were prepared by attaching freshly isolated protoplasts to glass coverslips or formvar/carbon-coated grids with poly-L-lysine and then bursting them either osmotically or by detergent treatment in the presence of a microtubule stabilizing buffer, and proved very useful for measuring the density and length of cortical microtubules.
Abstract: The arrangement of cortical microtubules in tobacco protoplasts is described using the following techniques: 1. Transmission electron microscopy (TEM) of thin sections of whole protoplasts, 2. TEM of negatively stained protoplast ghosts, and 3. Indirect immunofluorescence microscopy of protoplast ghosts. Ghosts were prepared by attaching freshly isolated protoplasts to glass coverslips or formvar/carbon-coated grids with poly-L-lysine and then bursting them either osmotically or by detergent treatment in the presence of a microtubule stabilizing buffer. Osmotic bursting of protoplasts yielded large pieces of plasma membrane with attached microtubules. These preparations proved very useful for measuring the density and length of cortical microtubules. Detergent treatment dissolved the plasma membrane and altered the distribution of cortical microtubules.
TL;DR: The hypothesis that there is a cholinergic projection from the GP to the cortex of the rat was tested by stimulating the GP while recording in the cortex and determining the effect of iontophoresed ACh-antagonists on the responses obtained.
TL;DR: The effects of continuous feeding of graded levels of ochratoxin A for eight weeks to male and female broiler chickens were investigated and a depression in body weight gain was observed in all groups receiving OA.
TL;DR: Chronic exposure to grain dust in nonallergic individuals appears to be associated with both increased prevalence of respiratory symptoms and increased nonspecific bronchial reactivity when compared to nonexposed control subjects.
TL;DR: Numerical results for a system with two parallel queues in which arriving customers always join the shorter queue are listed to discuss how fast the expected queue length converges toward its equilibrium, provided the arrivals are below the capacity of the service facility.
Abstract: This paper lists numerical results for a system with two parallel queues in which arriving customers always join the shorter queue. These results enable us to discuss how fast the expected queue length converges toward its equilibrium, provided the arrivals are below the capacity of the service facility. It also shows how fast the expected queue length increases in case the traffic flow is at or above the capacity of the service facility. Finally, it is shown that the system under consideration behaves very similar to a two-server queue.
TL;DR: It is concluded that GABA is released predominantly from neurons, and it is not known to what extent glutamine is returned from astrocytes to neurons to compensate for the release of GABA and glutamate.
TL;DR: In this article, the preparation of new complexes of the type (heteroarene)(cyclopentadienyl)iron hexafluorophosphate and (heterorene)bis(cyclopentadiyliron)-bis(hexafluorsophosphates) are described where heterorene is dibenzofuran or carbazole.
TL;DR: The starvation and cross-feeding experiment showed that both auxotrophs could be used in reconstruction experiments to develop enrichment-selection techniques for the isolation of more auxotrophics.
Abstract: A growth analysis of several presumptive “leaky” auxotrophs from Datura innoxia suspension cultures led to the discovery of an adenine-requiring cultures led to the discovery of an adenine-requiring cell strain (Ad1). Both Ad1 and Pn1, a pantothenate-requiring strain isolated earlier from these cultures, still require either adenine or pantothenate for growth after more than one year in culture. Attempts to select prototrophic revertants have failed. Ad 1 also grew well in a medium containing either 5-aminoimidazole-4-carboxamide ribotide or inosine instead of adenine; Pn 1 with pantoic acid alone but not at all in the presence of β-alanine or α-ketoisovalerate alone instead of pantothenate. Pn 1 cells starved of pantothenate for up to 4d and Ad1 of adenine for 10d or more resumed growth when transferred to appropriately supplemented media. Wild-type Datura cells grown on unsupplemented medium would not crossfeed the required nutrients to the auxotrophs. The starvation and cross-feeding experiment showed that both auxotrophs could be used in reconstruction experiments to develop enrichment-selection techniques for the isolation of more auxotrophs.