Showing papers by "Flinders University published in 1981"
TL;DR: The origins of substance P immunoreactive axons in the small intestine of the guinea-pig were investigated with an immunohistochemical technique in whole mount preparations and it is likely that the highly organised patterns of innervation by different substance P-containing neurons have specific roles in the intestine.
212 citations
TL;DR: The results demonstrate that the catecholamine (probably norepinephrine)-containing neurons which innervate the thoracic spinal cord are confirmed almost exclusively to the pons where they were found within the A5, A7 and subcoeruleus groups, as well as the ventral portion of the principal part of the locus coeruleus and the more caudal locus coercedus.
206 citations
TL;DR: In conclusion, VIP is contained in neurons that have the same projections as the enteric inhibitory neurons from the myenteric plexus to the taenia of the cecum.
151 citations
TL;DR: The iris and the cornea are supplied by sensory nerves containing substance P immunoreactive axons, which are found in the substantia propria, in the subepithelial layer and in the corneal epithelium.
140 citations
TL;DR: FMC7 is different from other monoclonal antibodies raised against B- lineage cells in that it recognizes only some subsets, presumably those at a late stage of maturation, and may contribute to the better characterization of the B-cell neoplasias.
139 citations
TL;DR: The results suggest that some of the nerve fibres localized in the heart by acetylcholinesterase (AChE) histochemistry are substance P-containing sensory fibres.
130 citations
TL;DR: In this paper, the origin of marine phosphorites in the East Australian continental margin was investigated and a model was proposed for the origin through the slow bacterial assimilation of phosphorus from seawater in an area of restricted sedimentation.
Abstract: Many models of the origin of marine phosphorites require a sediment rich in organic matter, which by decomposition releases phosphorus for the precipitation of carbonate fluorapatite1–7. This concept is useful in explaining contemporary phosphorite in areas of very high productivity off the coasts of Peru–Chile and South West Africa8–10 where there are high organic matter fluxes to the sea floor4–7,11. It does not explain the origin of marine phosphorite deposits which formed in regions of limited oceanic upwelling and productivity12–14. The East Australian continental margin, an area of phosphogenesis throughout the late Pleistocene and Holocene13,14, is a modern analogue of an ‘East Coast’ phosphogenic province15–17 with low productivity over the upper slope region where the most recent phosphorites have been found18. Evidence is reported here for the carbonate fluorapatite in the East Australian phosphorites being located within bacterial cellular structures, and a model proposed for the origin of these deposits through the slow bacterial assimilation of phosphorus from seawater in an area of restricted sedimentation.
126 citations
TL;DR: These experiments suggest that the persistent increase in peripheral resistance after lesions of the ventrolateral medulla results from destruction of neurons that normally act to inhibit sympathetic vasoconstrictor tone.
Abstract: We studied the effects of lesions in the ventrolateral medulla, in a region coinciding with the cell bodies of the Al group of catecholamine neurons. After bilateral electrolytic lesions at three contiguous rostrocaudal levels (obex and at 1 and 2 mm caudal to the obex), mean arterial pressure increased by 40 mm Hg in the conscious rabbit. This rise in pressure was associated with increased resistance in the distal aortic vascular bed and with profound bradycardia. Many lesioned animals developed respiratory distress in the first few postoperative hours and died with hemorrhagic pulmonary edema. In surviving rabbits, the distal aortic resistance remained raised throughout the 2-week observation period, but the blood pressure and heart rate returned to preoperative levels within 2 hours and then remained normal. Bilateral electrolytic lesions restricted to the level of the obex or to a level 1 mm caudal to tbe obex also caused transient hypertension and bradycardia, but most of the animals survived this more restricted damage and did not develop pulmonary edema. Micro-injections of kainic acid, a neurotoiin that specifically damages cell bodies, also caused transient hypertension and bradycardia, and after larger doses the rabbits died with acute pulmonary edema. Injections of 6- hydroxydopamine caused similar changes in pressure and heart rate, but doses necessary to destroy the Al cells caused nonspecific histological damage of an extent similar to that produced by electrolytic lesions. Sham-lesioned animals and those with control lesions in adjacent sites did not develop these cardiovascular changes. These experiments suggest that the persistent increase in peripheral resistance after lesions of the ventrolateral medulla results from destruction of neurons that normally act to inhibit sympathetic vasoconstrictor tone. It is our hypothesis that the increase in vascular resistance after the lesions results from destruction of the Al catecholamine cells within this ventrolateral region.
121 citations
TL;DR: It is suggested that cigarette smoking induces both of the cytochrome P450‐mediated pathways of theophyiiine metabolism but that N‐demethylation may be increased to a greater extent than 8‐hydroxylation.
Abstract: Differences in plasma theophylline clearance (ClT) and metabolism between smoking and nonsmoking normal subjects were examined by analysis of plasma and urinary theophylline concentrations and of urinary metabolite concentrations under steady-state oral dosing conditions. ClT in smokers (0.053 +/- 0.006 1 . hr-1 . kg-1) was greater than in nonsmokers (0.032 +/- 0.002 l . hr-1 . kg-1, p less than 0.005). Analyses of urinary metabolites revealed that clearance to l-methyluric acid (Cl1MU) and clearance to 3-methylxanthine (Cl3MX) were increased in smokers 1.99-fold and 2.10-fold over nonsmoking controls (P less than 0.005). Clearance to 1.3-dimethyluric acid (ClDMU) was also enhanced in smokers 1.68-fold compared to controls (P less than 0.01). The positive relationship between Cl1MU and Cl3MX in both smokers and nonsmokers (r = 0.98, P less than 0.001) supports the concept that two N-demethylation pathways for theophylline metabolism are under common regulatory control and involve a form of cytochrome P450 distinct from that mediating 8-hydroxylation of theophylline to DMU. These results suggest that cigarette smoking induces both of the cytochrome P450-mediated pathways of theophylline metabolism but that N-demethylation may be increased to a greater extent than 8-hydroxylation.
118 citations
TL;DR: Studies on marrow, leukaemic cells and cell lines suggest that the four antibodies react with distinct differentiation antigens which are absent from myeloblasts, appear at the promyelocyte, myelocyte or metamyelocyte stage and are expressed on all mature granulocytes.
Abstract: Summary. A series of four monoclonal antibodies has been prepared by hybridization of mouse myeloma cells with spleen cells from mice immunized with human blood granulocytes. The four antibodies all react specifically with granulocytes, failing to stain lymphocytes and other blood cells. Lymphocytic leukaemia cells are not stained, whereas myeloid leukaemia cells give a varied reaction with the antibodies. Studies on marrow, leukaemic cells and cell lines suggest that the four antibodies react with distinct differentiation antigens which are absent from myeloblasts, appear at the promyelocyte, myelocyte or metamyelocyte stage (depending on the antibody in question) and are expressed on all mature granulocytes.
101 citations
TL;DR: It is concluded that DFA applied to measures of dichotic monitoring performance gives a valid non-invasive classification of hemisphere specialization for language functions and that the classifications are reliable on retest.
TL;DR: In this paper, the penetration of an externally applied rotating magnetic field into a plasma cylinder is examined and it is shown that, provided the amplitude and rotation frequency of the field are suitably chosen, the penetration is not limited by the usual classical skin effect.
Abstract: The penetration of an externally applied rotating magnetic field into a plasma cylinder is examined. Steady-state solutions of an appropriate set of magneto-fluid equations show that, provided the amplitude and rotation frequency of the field are suitably chosen, the penetration is not limited by the usual classical skin effect. The enhanced penetration of the rotating field is accompanied by the generation of a unidirectional azimuthal electron current which is totally absent in a purely resistive plasma cylinder.
TL;DR: Plant movements are quite widespread in occurrence and all are most probably manifestations of a single physiological process, the change in volume of special motor cells, which provides a basic control of photosynthesis.
Abstract: The apparent and often spectacular movements of animals and insects, movements of the whole organism in relation to its surroundings arising from internally generated forces, have always been, by their very ubiquity, uppermost in our perception of motion in the living world. Movement in plants, generally of one organ in relation to the whole plant, whilst sometimes spectacular, have often in the past been seen as rather esoteric events, amusing perhaps, but of little importance in the general biological scheme of things. However, this is not so; plant movements are quite widespread in occurrence and all are most probably manifestations of a single physiological process, the change in volume of special motor cells. One particular movement, the opening and closing of stomata, which provides a basic control of photosynthesis, is of fundamental importance to the existence of the whole biosphere.
TL;DR: It is concluded that societal influences seem to have an influence on the number of transsexuals presenting as patients and whether these factors also influence aetiology and development of transsexualism.
Abstract: Several hypotheses with regard to the influence of societal factors including the rigidity of the society with regard to sex roles, sexual equality and homosexual behaviour were tested comparing prevalence, incidence and sex ratio of transsexualism between Sweden and Australia, two societies which differ with respect to these factors while otherwise remaining comparable as Western democratic societies of about the same size and level of technological development. Significant differences were found between the two countries in both frequency and sex ratio of transsexualism. These findings are discussed and it is concluded that societal influences seem to have an influence on the number of transsexuals presenting as patients. Further research is needed to assess whether these factors also influence aetiology and development of transsexualism.
01 Dec 1981
TL;DR: PEGASUS, a free falling, acoustically tracked, absolute velocity profiler has been developed as discussed by the authors, which is tracked relative to two expendable, bottom-mounted beacons, temperature, and pressure data are stored every 8 s in a microprocessor based data logger.
Abstract: PEGASUS, a free falling, acoustically tracked, absolute velocity profiler has been developed. The instrument is tracked relative to two expendable, bottom-mounted beacons. The acoustic travel times from the beacons, temperature, and pressure data are stored every 8 s in a microprocessor based data logger. Velocity profiles, accurate to 1 cm s −1 , are derived from the trajectory of PEGASUS. Volume transports can be computed directly from the profiles and fine structure in the vertical can be observed. The new instrument is compact, lightweight, inexpensive to fabricate, and easy to use at sea.
TL;DR: It is suggested that other amacrine cell sub-classes, defined in terms of their putative transmitter, may show specific patterns of cell body location and size, and terminal arborisation.
TL;DR: Bilateral ventrolateral medullary lesions produced a greater than 50% reduction in the gain of the mean arterial pressure-distal aortic flow curves evident throughout the 2-week observation period, indicating a persistent severe attenuation in the sensitivity of the baroreceptor-vanoconstriction reflex, similar in magnitude to that obtained after peripheral α-adrenergic blockade.
Abstract: We have studied arterial baroreeeptor reflexes in the conscious rabbit after bilateral electrolytic lesions of the ventrolateral medulla, coinciding with the Al group of catecholamine cells. Baroreflex function was determined from the changes induced in heart period and distal aortic blood flow in response to graded alterations in mean arterial pressure produced by inflation of balloon occluders around the thoracic inferior vena cava and the upper abdominal aorta. Distal aortic blood flow was determined using a Doppler ultrasonic flowmeter placed around the lower abdominal aorta. There were no significant changes in baroreflex function in sham-operated animals in which electrodes were inserted without the passage of current. The gain of the baroreceptor-heart period curves was reduced by approximately 50% at 40 minutes, 4 hours, and 24 hours after the lesions, compared to preoperative values and to values at corresponding times in sham-operated animals, but was restored to control levels 2 weeks after the lesions. Ventrolateral medullary lesions therefore destroy neurons that normally act to facilitate the baroreceptor-heart period reflex, though it is clear that other neurons not affected by the lesions also participate in the reflex. Bilateral ventrolateral medullary lesions produced a greater than 50% reduction in the gain of the mean arterial pressure-distal aortic flow curves evident throughout the 2-week observation period, indicating a persistent severe attenuation in the sensitivity of the baroreceptor-vanoconstriction reflex, similar in magnitude to that obtained after peripheral α-adrenergic blockade. It is our hypothesis that the persistent loss of the baroreceptorvasoconstriction reflex results from destruction of Al noradrenergic nerves that normally act in concert with the afferent connections of arterial baroreceptor reflexes to inhibit sympathetic vasoconstrictor tone and that the temporary loss in sensitivity of the baroreceptor-heart period reflex is caused by destruction of Al neurons th»t participate in the control of heart rate.
TL;DR: The authors found that neither aging nor cohort variables alone accounted for the expected positive correlation between age and job satisfaction, however, the correlation became unsubstantial when the joint effects of aging and cohort variables were partialled out.
Abstract: Previous research has consistently shown a small positive correlation between age and job satisfaction. This correlation could result from influences associated with aging or cohort membership or both. These possible explanations were tested using a representative 1/2% sample of employees in metropolitan Adelaide. From interviews/questionnaires, measures were obtained of variables associated with aging (skill-utilization, influence, variety and income) and of variables associated with cohort membership (desired skill-utilization, desired influence, desired variety and education). Using partial correlations, it was found that neither aging nor cohort variables alone accounted for the expected positive correlation between age and job satisfaction. However, the correlation became unsubstantial when the joint effects of aging and cohort variables were partialled out. This finding was interpreted in terms of decreasing discrepancy between desired and perceived job attributes with increasing age.
TL;DR: In this article, the momentum distribution of electrons in the ground state of atomic hydrogen was measured using the non-coplanar symmetric (e, 2e) technique, which is the first direct measurement of the electron momentum distribution in a ground state.
TL;DR: Axons of the A1-group of catecholamine neurons in the ventrolateral medulla project toward the ipsilateral nucleus tractus solitarii in a relatively compact band at the level of the obex.
Abstract: The distribution and interconnections of brainstem catecholamine cell groups thought to be important in cardiovascular control were studied using histochemical and ultrastructural techniques in the rabbit. Lesions and microinjections of horseradish peroxidase (HRP) were made in the nucleus tractus solitarii in the dorsomedial medulla, and in the ventrolateral medulla. After lesions of the dorsomedial medulla the fluorescence intensity of the A1-group of catecholamine neurons was increased, and swollen axons could be seen coursing from the ventrolateral medulla toward the lesions on the same side, but not the opposite side. Most of these axons ran in a band about 2 mm in width, centered at the level of the obex. Electron microscopically, specific cells, identified as A1-catecholamine neurons, showed evidence of chromatolysis after the dorsomedial lesions. Following injection of HRP into the nucleus tractus solitarii. A1-catecholamine cells in the ventrolateral medulla on the same side contained the reaction product. Lesions of the ventrolateral medulla did not produce evidence of a reciprocal projection of A2-catecholamine neurons toward the ventrolateral medulla. Thus axons of the A1-group of catecholamine neurons in the ventrolateral medulla project toward the ipsilateral nucleus tractus solitarii in a relatively compact band at the level of the obex. On the other hand, the A2-group of catecholamine neurons in the dorsomedial medulla does not appear to send projections toward the A1-group.
TL;DR: A detailed study of the structure and metamorphic history of 400 km2 of the Aileu Formation showed it has a complex history of penetrative deformation but the structure is coherent.
TL;DR: It has been concluded that the formation of plasma esterified cholesterol occurs in the HDL3 subfraction, in man, who possesses adequate levels of esterify cholesterol transfer activity, and in pigs, which lack transfer activity.
TL;DR: Noradrenergic axons in the enteric plexuses of the guinea-pig ileum have been identified at the ultrastructural level using three techniques: the chromaffin reaction, localization of dopamine-β-hydroxylase (DBH) with horseradish peroxidase-conjugated antibody, andin vivo andin vitro loading with 5-Hydroxydopamine (5-OHDA).
Abstract: Noradrenergic axons in the enteric plexuses of the guinea-pig ileum have been identified at the ultrastructural level using three techniques: the chromaffin reaction, localization of dopamine-β-hydroxylase (DBH) with horseradish peroxidase-conjugated antibody, andin vivo andin vitro loading with 5-hydroxydopamine (5-OHDA)
TL;DR: It is suggested that different pathogenetic mechanisms are responsible for these two forms of MG.
TL;DR: From their structure, submucous neurons appear to form a more homogeneous population than myenteric neurons, and are more likely to be freely exposed to substances diffusing in the extraganglionic tissue than are neurons of sympathetic ganglia.
Abstract: A fine structural study was made of the ganglia, neurons, Schwann cells and neuropil of the submucous plexus of the guinea-pig ileum. The arrangement of the plexus as seen by light microscopy is briefly described. Submucous ganglia are small, containing an average of eight neurons per ganglion (compared with 43 in myenteric ganglia) and are connected with each other by fine nerve strands. The cell bodies of neurons and Schwann cells and a neuropil consisting of neuronal and Schwann cell processes from the ganglia. No other cell types or blood vessels are found within the ganglia. Ganglia are surrounded by a continuous basal lamina but lack a well-defined connective tissue investment. The glial investment of neurons is incomplete: many neurons lie directly beneath the basal lamina with no intervening Schwann cell processes, and the plasma membranes of adjacent neurons are often directly apposed over large areas. Other areas of apposition occur between the cell bodies and processes of neurons and Schwann cells. Desmosome-like membrane specializations may be seen between neurons and other neurons or Schwann cells. Submucous neurons could not be categorized according to size, shape, organelle content or types of processes. Processes emerging from nerve-cell bodies were placed into four broad categories on the basis of shape and microtubule content. Many bundles of closely apposed small nerve profiles lacking intervening Schwann processes are found in the neuropil in addition to a large number of vesiculated varicosities, some of which are directly apposed to the plasma membranes of nerve-cell bodies. A small proportion of vesiculated profiles from synapses with nerve cell bodies, their processes and profiles in the neuropil. From their structure, submucous neurons appear to form a more homogeneous population than myenteric neurons. Because of their incomplete investment they are more likely to be freely exposed to substances diffusing in the extraganglionic tissue than are neurons of sympathetic ganglia.
TL;DR: It is suggested that ovarian hormones could regulate the contents of the uterine lumen by altering the structure extent of the tight junctions which connect the epithelial cells enclosing the lumen.
Abstract: Freeze-fracture techniques have been used to study tight junctions on the lateral plasma membrane of cells of the luminal epithelium of the rat uterus under various hormonal regimes.
TL;DR: In vitro and in vivo studies were undertaken to examine factors affecting the volume and temperature of the injectate, catheter thermistor and computer performance, effect of respiration, use of cold versus ambient temperature, and the interpretation of measurements.
Abstract: Errors in thermodilution cardiac output measurement were quantitated to determine the order of accuracy of routine measurements performed by unskilled personnel. In vitro and in vivo studies were undertaken to examine factors affecting the volume and temperature of the injectate, catheter thermistor and computer performance, effect of respiration, use of cold (0-4 degrees C) versus ambient temperature (20-25 degrees C) injectate, and the interpretation of measurements. Ambient temperature injectate incurred unacceptably large errors; cold injectate (injections were timed with respiration) produced variations in performance by equipment and personnel which accounted for only 2% of the variation between successive measurements. Real changes in cardiac output and inherent variability of the downslope of the thermal curve, necessitating an empirically based calculation, account for up to 10% variation between successive measurements. When cold injectate was used, and the average of three corrected measurements taken, thermodilution cardiac output measurements were within 10% of a simultaneous dye dilution measurement.
TL;DR: In this article, the authors compare photoelectrochemical cyclic voltammograms with ordinary cyclic VVMs and find peaks corresponding to the reduction of PbO to Pb, and to the oxidation of pBO to α-PbO 2.
TL;DR: An histological examination of N. alexis kidney revealed that two sites of solute transfer from urine to medulla may be operative, consistent with reports in the literature on another desert rodent Psammomys.
TL;DR: A short review of nucleation-growth-collision (N-G-C) theory is presented in this article, where stress is placed on recent developments, including lattice models, mathematical models which use theorems in integral geometry, time-varying driving forces, underpotential (i.e. non-bulk) deposition.