bluuebunny/crossref_metadata_2025_split huggingface dataset:
ELECTROPHYSIOLOGICAL INVESTIGATIONS ON THE PIGEON'S OPTIC TECTUM
Authors: Bilge M. 
Published: December 2014

Electrical responses of the cells at different depths of the pigeon's optic tectum to different visual stimuli were recorded.Point to point representation of the upper visual field on the dorsal surface of the tectum was obtained as a projection on a horizontal stereotaxic plane.Different units in the stratum griseum et fibrosum superficiale of the tectal cortex are all sensitive to stationary and moving stimuli and all have very small (2–3 degrees in diameter) visual receptive fields. The most noticeable difference between units from the superficial sublayers of the stratum griseum et fibrosum superficiale and those from the deeper sublayers of the stratum griseum et fibrosum superficiale is that the deeper units show much more rapid habituation to repetitive stationary stimuli, while they remain equally sensitive to all types of moving visual stimuli. All the units in the stratum griseum centrale are either insensitive to stationary stimuli or habituate very rapidly to them. They are very sensitive to moving stimuli. These movement detectors have large receptive fields mostly rectangular in shape with long axes vertical or horizontal but never oblique.The nucleus isthmi showed different types of special units all with large receptive fields, the majority of which had indefinite boundaries. A small group had sharp boundaries and rectangular fields and resembled those seen in the stratum griseum centrale. These units are insensitive to stationary target and habituate very rapidly to steadily moving targets. Some of them behave as if they were sensitive to more complex types of movement.
THE EFFECT OF GLUCOSE, GALACTOSE AND SORBITOL ON GASTRIC EMPTYING IN THE YOUNG PIG
Authors: Reed J. H. , Kidder D. E. 
Published: December 2014

The emptying times of glucose solutions of different concentrations by the stomach of the young pig have been compared. The emptying of glucose solutions has also been compared with that of galactose, sorbitol and sodium chloride of similar osmolarity.The more concentrated the glucose solution, the more slowly it is emptied, as is reported in other species. The emptying rate of galactose is similar to that of glucose and slower than sorbitol which is emptied at a similar rate to sodium chloride.
MEASUREMENT OF CARBON DIOXIDE PRODUCTION IN SHEEP BY ISOTOPE DILUTION
Authors: Whitelaw F. G. , Brockway J. M. , Reid R. S. 
Published: December 2014

Sheep were given continuous subcutaneous infusions of NaH14CO3 at a rate of 0·03 ml./min, 90–150 nCi/min, for periods of 8 to 36 hr and the rate of entry of metabolic CO2 into the body pool of CO2 was calculated from the relationship between the rate of infusion of radioactivity and the specific activity (SA) of CO2 in blood or urine samples. In preliminary experiments, the variability from hour to hour in the SA of CO2 was found to be two to three times greater for blood than for urine samples and, in urine, was two times greater under a twice‐daily feeding regime than under continuous feeding conditions. An infusion period of about 8 hr was required for the initial equilibration of the infused activity with the body pool of CO2.A close relationship was found to exist between CO2 entry rates derived from the SA of CO2 in samples of urine or expired air collected over 24 hr, and either total CO2 production or total heat production as measured in a closed‐circuit respiration chamber. On average, entry rate values calculated from urine samples overestimated total CO2 production by 3·7 per cent and those calculated from expired air overestimated by 2·2 per cent. The regression equations describing the relationships between CO2 entry rate and CO2 production or heat production had residual standard deviations ranging from 4·3 to 7·5 per cent of the mean values.In sheep given two meals per day there was a reduction in the SA of CO2 in urine immediately after eating. Since feeding had no apparent effect on the rate of transfer of 14CO2 from rumen to urine it was concluded that the depression in SA resulted from a general increase in metabolic activity consequent upon the absorption of nutrients from the gut rather than from dilution with unlabelled CO2 produced in rumen fermentation. In certain sheep the postprandial depression in SA was very marked and appeared to be associated with a reduction in urine pH. Attempts to recreate this condition in penned sheep and to explain it by reference to changes in the acid‐base status of the blood were not entirely successful.
VARIATIONS IN ASPHYXIAL GASPING WITH FETAL AGE IN LAMBS AND GUINEA‐PIGS
Authors: Dawes G. S. , Fox H. E. , Richards R. T. 
Published: December 2014

The time to the last gasp after tying the umbilical cord was measured in fetal lambs and guinea‐pigs of different gestation ages; body temperature was maintained. At two‐thirds of term the times to the last gasp were slightly but significantly greater than at full term in both species. But at about 0·34 (lamb) and 0·46 of term (guinea‐pig) the times to the last gasp were very much less than in mature fetuses.In lambs a third of the way through gestation the short time to the last gasp could not be attributed to hypoglycaemia, circulatory collapse or neuro‐muscular failure. The results suggest that at this age the respiratory centre may be more susceptible to asphyxia, yet post‐asphyxial recovery occurred rapidly.
THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS
Authors: Draper M. H. , Davidson Maida F. , Wyburn G. M. , Johnston H. S. 
Published: December 2014

The fibrous membrane forming region of the isthmus of the oviduct of Gallus Domesticus forms the upper two thirds of the anatomical isthmus. The secreting surface of the isthmus is arranged in a series of longitudinal ridges. The mucous membrane consists of a surface epithelium of columnar cells beneath which is a layer of tubular glands. In the membrane forming part of the isthmus the tubular gland cells are filled with prominent secretory granules, hence the name granular isthmus. The tubular glands of the lower third of the isthmus have few prominent granules and the region has a characteristic reddish tinge; hence the name red region of the isthmus is appropriate.In the granular isthmus there are three types of surface epithelial cell. About half are ciliated cells. These have nuclei situated towards the apex of the cell and contain scattered electron dense granules, particularly towards the apex. Lysosome‐like bodies are also present. Alternating with the ciliated cells are secretory cells termed granular cells which tend to bulge out of the surface to form blebs which are filled with aggregations of granules which are usually electron dense. This material is PAS positive and alcian blue negative in histological preparations. The nuclei are situated basally and they are usually associated with granular endoplasmic reticular (GER) profiles and cisternae filled with homogeneous material. Golgi substance is not prominent. Some cells contain masses of small granules morphologically resembling glycogen particles. A third type of cell constitutes about 8% of the surface epithelium. It contains columns of mitochondria running from the base to the apex of the cell. There are no cilia or secreting granules present, yet the apex bulges above the mucosal surface. The function of these mitochondrial cells is obscure; there is no movement of water, Na+ or K+ into the granular isthmus lumen. The tubular gland cells are filled with secretory granules ranging from 0·2 µm to 3 µm. Most of the granules are of uniform electron density but granules with a wide variety of density pattere are seen. Microvilli are prominent as are mitochondria often associated with GER profiles. The GER profiles can be prominent and they have a remarkable beaded appearance due to an altemation of dense and pale areas. Golgi material is prominent and complex when it is visible in cells depleted of secretory material. The granules are not secreted as such. Amorphous material condenses into a membrane fibre in the lumen of a tubular gland and by the time these fibres reach the luminal surface of the oviduct they have the characteristic core and mantle structure of the basic fibre of the shell membrane.
THE EFFECT OF ACETYLSALICYLIC ACID ON PLATELET ADHESION IN THE INJURED ABDOMINAL AORTA
Authors: Sheppard B. L. 
Published: December 2014

The effect of a single oral dose of acetylsalicylic acid (ASA) on platelet adhesion in the rabbit abdominal aorta following a standard mechanical removal of the endothelium has been observed with both the scanning and transmission electron microscopes, in conjunction with studies on the agglutination properties of the platelets in vitro. It was found that the ASA did not prevent adhesion of platelets to the subendothelial surface although they did not appear to be adhering to the exposed collagen fibres but rather to endothelial basement membrane and microfibrils of the internal elastic lamina, often in small clumps. A large number of leucocytes were also observed adhering to the surface denuded to endothelium.The platelets obtained from ASA treated animals were morphologically normal, but unlike platelets obtained before treatment, did not adhere to collagen fibres in vitro; even when ADP was added the platelets adhered to one another but not to the collagen.
THE USE OF SUGARS AND FLUORODINITROBENZENE (FDNB) TO DIFFERENTIALLY LABEL RED CELL MEMBRANE COMPONENTS INVOLVED IN HEXOSE TRANSFERS
Authors: Eady R. P. , Widdas W. F. 
Published: December 2014

The possibility of differentially labelling human red cell membrane components involved in the facilitated transfer of hexoses by incubation with 1‐fluoro‐2,4‐dinitrobenzene (FDNB) irr the presence of different sugars, one with a potentiating effect on the inhibitory reaction and the other with a protective effect, has been explored.After incubation with 14C‐FDNB, membrane proteins were subjected to SDS polyacrylamide gel disc electrophoresis and gel fractions were assessed for radioactive labelling. Early fractions from cells incubated with 2‐deoxyglucose (the potentiating sugar) carried more label than those from cells incubated with ethylidene glucose (the protecting sugar).In both types of incubations the bulk of the label was taken up nonspecifically by intracellular material and membrane proteins but this technique and a method based on the preferential uptake of D‐glucose from a D‐/L‐glucose mixture point to fractions which merit further study by methods of increased resolving power.
THE EFFECT OF ISOPRENALINE ON THE CARDIAC AND RESPIRATORY RESPONSES TO EXERCISE
Authors: Silverman M. , Zeidifard E. , Paterson J. W. , Godfrey S. 
Published: December 2014

The effects of intravenous isoprenaline on the response to exercise were studied in five normal adults. Each subject exercised on a bicycle ergometer at work loads of 50, 100, 150 watts. At each work load ventilation and gas exchange were measured; cardiac output and stroke volume were calculated using the Indirect (CO2) Fick method.Isoprenaline produced no significant changes in oxygen consumption or in minute ventilation. Heart rate was significantly increased by isoprenaline in all subjects, the increment becoming smaller at higher workloads. In four of the subjects cardiac output was increased by isoprenaline, stroke volume being virtually unchanged. In the remaining subject cardiac output was unchanged with a fall in stroke volume.
CHOLINE ACETYLTRANSFERASE IN THE HEART AND SALIVARY GLANDS OF THE RAT AFTER PHYSICAL TRAINING
Authors: Ekström J. 
Published: December 2014

After physical training of rats for 11–14 weeks both weight of atria and weight of ventricles were higher in relation to body weight than those of untrained controls. The capacity to synthesize acetylcholine, as judged by the activity of choline acetyltransferase, was increased in the atria of the trained rats, but the enzyme activity did not change in the ventricles. This result seems to support the concept of a high cholinergic activity as one cause of the low resting heart rate after training.Salivary glands are known to take part in thermo‐regulation in rats. After the period of training increased submaxillary gland weight was found in relation to bodyweight, but two other major salivary glands were unchanged. Although the training seems to have caused increased secretory activity of the submaxillary gland, no changes in the activity of choline acetyltransferase were noticed.
FLOW DISTURBANCES IN GLASS MODELS OF ANEURYSMS AT LOW REYNOLDS NUMBERS
Authors: Stehbens W. E. 
Published: December 2014

Flow in glass models, simulating fusiform, cylindrical, spherical and lateral saccular aneurysms, was examined by experimentation using the dye injection technique. Aneurysmal dilatations on straight tubes did not induce turbulence at Reynolds numbers below the critical level for turbulence in a straight tube (2000). A lateral aneurysm associated with a deflection of the distal tube (20°) induced turbulence distal to the aneurysm at a Reynolds number of 1100.In all models, waves in the dye within the aneurysm and in the parent tube immediately distal to the aneurysm were observed at Reynolds numbers considerably below critical levels for turbulence. This wave motion, due to oscillations of the dye filaments at the junction of the tube and the distal end of the aneurysm, is possibly a jet edge phenomenon.
THE METABOLIC EFFECTS OF STRENUOUS EXERCISE: A COMPARISON BETWEEN UNTRAINED SUBJECTS AND RACING CYCLISTS
Authors: Rennie M. J. , Jennett Sheila , Johnson R. H. 
Published: December 2014

Previous investigations have suggested that post‐exercise ketosis is more marked in untrained subjects than in athletes. The present study was designed to exclude the possibility that the untrained subjects worked relatively harder. Four racing cyclists and five untrained subjects were studied during and after 20 min strenuous exercise on a bicycle ergometer. The work loads were adjusted so that the cyclists worked at least as hard, in terms of the heart rate attained, as the untrained subjects. Observations were made of respiratory gas exchange; blood samples were taken at rest, during and after the exercise and were analysed for ketone‐bodies and other metabolites, insulin and growth hormone.The racing cyclists worked at 1070 kpm/min with heart rate of 179·5 beats/min and oxygen consumption of 48 ml./min per kg body‐weight (means). The values for the untrained subjects were 715, 167 and 35 respectively. After exercise the concentration of ketone‐bodies in the blood increased progressively in both groups, reaching highest measured values 150 min after exercise. The increase was much smaller for all the racing cyclists. We conclude that post‐exercise ketosis is less in athletes even when they work as hard as or harder than untrained subjects.
THE MOVEMENT OF AN UNEMULSIFIED OIL TEST MEAL AND AQUEOUS‐AND OIL‐PHASE MARKERS THROUGH THE INTESTINE OF NORMAL AND BILE‐DIVERTED RATS
Authors: Brand S. J. , Morgan R. G.H. 
Published: December 2014

An unemulsified oil test meal containing aqueous‐ and oil‐phase markers (PEG and 3H labelled triether) was fed to control and bile fistula rats. PEG moved ahead of the lipid phase in all groups, and was of limited value as a marker for the test meal. Triether was an excellent marker for studies of gastric emptying. An unexpectedly high correlation was seen between the triether and the test meal and its digestion products in the intestine. The results suggest that triether is a valid marker for following the movement of lipid through the bowel under the conditions of this study. Triether/fat ratios indicated that fat absorption occurred largely from the upper small bowel in control animals and from the lower small bowel in the absence of bile.Bile diversion resulted in more rapid gastric emptying initially, but very slow gastric emptying of the last part of the oil test meal. Intestinal transit of test meal or either marker was not significantly affected by bile diversion. No evidence for a direct effect of bile diversion on gastrointestinal motility was found.
THE INCIDENCE AND PROPERTIES OF β AXONS TO MUSCLE SPINDLES IN THE CAT HIND LIMB
Authors: McWilliam P. N. 
Published: December 2014

The distribution of β axons to muscle spindles in the tenuissimus and abductor digiti quinti medius (A.D.Q.M.) muscles of the hind limb of the cat was determined by testing the action of single motor axons, capable of producing extrafusal contraction, isolated in the ventral spinal roots on the discharges of individual muscle spindle primary sensory endings recorded in the dorsal spinal roots. The proportion of spindles with β innervation was 41% in A.D.Q.M. and 30% in tenuissimus. The proportion of fast motor axons that were β axons was 28% in the A.D.Q.M. and 11% in tenuissimus; usually each , β axon innervated a single spindle while no spindle received more than two β axons. The β axons were dynamic in nature and those to any one muscle tended to have slightly lower conduction velocities than the α axons though some overlap did occur.The extent to which β axons can account for the fact that in isolated spindles axons selective to either nuclear bag or nuclear chain fibres are found in about equal proportions whereas a ratio of three static to one dynamic γ axons is found electrophysiologically is discussed. An explanation for the low incidence of β innervation previously found electrophysiologically and the considerably higher incidence found histologically is given.
THE EFFECTS OF VAGOTOMY ON VENTILATION AND BLOOD GAS COMPOSITION IN DOG, SHEEP AND RABBIT
Authors: Kashani Monir , Haigh A. L. 
Published: December 2014

The influence of vagotomy on resting arterial blood gases (PaCO2 and PaO2) and on the ventilatory responses to hypercapnia and hypoxia was studied in three different species of anaesthetized animals. After bilateral cervical vagotomy resting PaCO2 generally declined. In the dog, where this was studied more fully, resting PaCO2 declined significantly (8·13±0·67 mm Hg) over several hours, but PaO2 changes were not significant.After vagotomy tidal volume (VT), but not frequency (f), increased with increasing chemical drive. It is concluded that the increase in frequency in response to increased CO2 or decreased O2 is dependent on the vagal mechanisms.Minute volume, fractional inspiratory CO2 (VE, FICO2) and minute volume, fractional inspiratory O2 (VE, F102) relationships have been determined. Although vagotomy may not decrease the response of minute volume of ventilation in the lower part of VE, FICO2 curves (mild hypercapnia), it flattened the upper parts of the curves in sheep and rabbits, and to a lesser extent in dogs; it seemed that there was little species difference in this respect. Ventilatory responses to graded hypoxia were close to or slightly higher than pre‐vagotomy values throughout the VE, FIO2, curves in all animals.
ACTIVITIES OF MIXED FUNCTION OXIDASES, UDP‐GLUCURONYL TRANSFERASE AND SULPHATE CONJUGATION ENZYMES IN GALLIFORMES AND ANSERIFORMES
Authors: Bartlet A. L. , Kirinya L. M. 
Published: December 2014

The activities of certain drug metabolizing enzymes have been measured in liver and kidney slice preparations from domesticated birds. Aminopyrine demethylase activity was significantly lower in liver slices from the duck (Aylesbury x Pekin, Khaki‐Campbell) than from the rat (Wistar), and in the Aylesbury x Pekin duck lower than in the turkey (Triple 6 FLX), chicken (Brown Leghorn, Rhode Island Red x Light Sussex) and goose (Emden x Doulouse). The microsomal cytochrome P—450 was lower in duck liver (Aylesbury x Pekin) than in rat liver, and the aniline hydroxylase and aminopyrine demethylase activities in a 10,000 g supernatant fraction of liver were lower in duck preparations (Aylesbury x Pekin, Khaki‐Campbell) than rat preparations. These observations suggest that the duck is likely to be susceptible to drugs which are metabolized by the cytochrome P‐450 containing mono‐oxygenases.UDP‐Glucuronyl transferase activity was not detectable in liver and kidney slices from two mature geese. This observation was not the outcome of a deficiency of UDP‐glucuronic acid, rapid breakdown of glucuronide by β‐glucuronidase or the presence of a substance inhibitory to UDP‐glucuronyl transferase. Liver slices from geese, ducks (Aylesbury x Pekin) and chickens contained low UDP‐glucuronyl transferase and high sulphate conjugation enzyme activities, whereas the reverse was found in Khaki‐Campbell ducks. The activities of UDP‐glucuronyl transferase and the sulphate conjugation enzymes were both relatively high in liver slices from the turkey and rat.The kidney contained lower enzyme activities than the liver except in the duck (Aylesbury x Pekin), in which low activities of aminopyrine demethylase and UDP‐glucuronyl transferase were present in slices of both organs.In liver slices from chickens and geese the activities of aminopyrine demethylase and the sulphate conjugation enzymes were similar in mature and immature birds, and the activity of UDP‐glucuronyl transferase was considerably higher in chicks and goslings than in mature birds of the same species.In the chick the activities of aminopyrine demethylase, UDP‐glucuronyl transferase and the sulphate conjugation enzymes were higher in the duodenum than the remainder of the alimentary tract. The activities of these enzymes in pieces of duodenum were as high as those in slices of liver.The inclusion of sulphate in the incubation medium produced a significant increase in the synthesis of p‐nitrophenyl sulphate in liver slices and not kidney slices except those from the duck. The kidney slices seemed to produce sufficient sulphate for the reaction of the sulphate conjugation enzymes to proceed at the maximum rate, but the liver slices did not do so.
ON THE EXISTENCE OF PARASYMPATHETIC MOTOR NERVES TO THE SUBMAXILLARY GLAND OF THE DOG
Authors: Emmelin N. , Gjörstrup P. , Thesleff P. 
Published: December 2014

Duct pressure and salivary flow were recorded in submaxillary glands of anaesthetized dogs, to study whether parasympathetic stimulation caused effects referable to activity in myoepithelial cells. At fairly low frequency of stimulation, e.g. 3 Hz, the pressure curve had two distinct components, with an initial steep and a secondary gradual rise. It resembled that obtained on sympathetic stimulation, where the first phase is ascribed to myoepithelial contraction, the second phase to secretion. When parasympathetic stimulation ceased, there was first a steep fall, then a more gradual decline of the pressure. The steep fall was of the same magnitude as the steep rise; both increased with the frequency of stimulation. The size of the initial fall was fairly independent of the pressure level from which it started. Such a steep fall did not occur subsequent to parasympathetic stimulation if the myoepithelial cells were already in a state of strong contraction caused by sympathetic impulses or bradykinin. The phase of steep fall was inferred to be due mainly to relaxation of contracted myoepithelial cells, the following decline to back‐flow of fluid into the gland.The salivary flow rate was highest at the beginning of a period of parasympathetic stimulation, particularly if the duct system was well filled and the saliva thin. It was concluded that myoepithelial contraction had initially expelled saliva. A brief period of parasympathetic stimulation while a slow basal secretion at constant rate was going on was found to accelerate this flow, and afterwards there was a transient deceleration of the flow. Acceleration was attributed partly to myoepithelial contraction, mainly to superimposed secretion; retardation to myoepithelial relaxation. The effect appeared independently of the way in which the basal flow was evoked, and the retardation resembled that seen after sympathetic stimulation or bradykinin.