bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF HYPERTHERMIA ON THE SYSTEMIC AND PULMONARY CIRCULATION OF THE OX (Bos taurus)
Authors: Whittow G. C.
Published: December 2014

The cardiac output, arterial blood pressure, pulmonary arterial pressure, heart rate, blood volume, respiratory rate and rectal temperature of the unanæsthetized ox have been measured at environmental temperatures of 150° C. and 400° C. (low humidity) and also during hyperthermia induced by increasing the humidity of the hot environment (400° C.). Derived values for total peripheral resistance, central blood volume and cardiac work were obtained from the measured data.

The cardiac output, central blood volume and respiratory rate were significantly higher, while the mean blood pressure and calculated total peripheral resistance were significantly lower, in the hot dry environment than they were at 15° C. These results seemed to be consistent with the hypothesis that a peripheral vasodilatation and an increased venous return occurred in the hot dry environment.

The increase in systemic arterial blood pressure during hyperthermia was attributed to the concomitant increase in cardiac output because the total peripheral resistance diminished. The increase in the cardiac output was the result of an increased heart rate. At a rectal temperature of 41.50° C. the stroke volume of the heart was considerably lower than its control value at an environmental temperature of 15° C. The work of the heart was increased during hyperthermia.

The increased respiratory activity in hyperthermic animals was associated with a diminution of the mean pulmonary arterial pressure and an increase in the central blood volume.

No statistically significant differences in plasma or blood volumes of the animals were recorded between environments of 15° C. and 40° C. (low humidity) and 40° C.(high humidity). The plasma volume tended to diminish during hyperthermia while the blood volume tended to be maintained close to its control value as a result of an increase in the proportion of red cells in the blood.

At a rectal temperature of 41.5° C. none of the animals was in a state of circulatory failure, but there was evidence that their cardiovascular systems were severely stressed at this temperature.
CONTINUOUS CINEMATOGRAPHY OF HUMAN LYMPHOCYTES CULTURED WITH A PHYTOHÆMAGGLUTININ INCLUDING OBSERVATIONS ON CELL DIVISION AND INTERPHASE
Authors: Roberts K. B. , Marshall W. H.
Published: December 2014

Continuous time‐lapse cinematography of human small lymphocytes, in tissue culture with phytohæmagglutinin, has been carried out by confining the cells in microchambers. It has been shown that small lymphocytes can enlarge and divide after incubation in such cultures. The large cells so formed, and the daughter cells produced by their division, move in a characteristically lymphocytic fashion. The daughter cells have been shown to double their size and then themselves divide. Evidence is presented which suggests that a line of large proliferating cells with lymphocytic motility is formed and that these continue for some days to reproduce their own kind rather than differentiate into any other cell type. The time taken for cell division is about 30 min. Interphase has been measured on two occasions giving times of 23 and 38½ hr. respectively.
THE ROLE ÔF GROWTH HORMONE IN THE MOBILIZATION OF FUEL FOR MUSCULAR EXERCISE
Authors: Hunter W. M. , Fonseka C. C. , Passmore R.
Published: December 2014

Plasma human growth hormone (HGH) levels were consistently below the threshold of sensitivity of present methods of detection (<31 µmg./ml.) in adults before rising in the morning. Moderate exercise in the post‐absorptive state caused a rise up to 50‐fold in 1 hr. This rise did not occur if carbohydrate was made available during the exercise. In the second hour of walking a fall in plasma HGH occurred, and there was a rise 1‐2 hr. later. It appears probable that HGH, through its lipotrophic action, has an important rôle in initiating and maintaining the mobilization of depot fat during exercise.
UPTAKE AND METABOLISM OF 14C‐LABELLED TRIGLYCERIDE BY RETICULO‐ENDOTHELIAL CELLS
Authors: Day A. J. , Fidge N. H. , Gould‐Hurst P. R. S. , Wahlqvist M. L. , Wilkinson G. K.
Published: December 2014

The uptake and metabolism of 14C‐labelled triglyceride by R.E. cells in rat lymph nodes has been investigated. After the intraperitoneal injection of a corn oil emulsion containing glyceryl tripalmitate‐1‐14C uptake of labelled triglyceride by the R.E. cells in the nodes occurs. The uptake is accompanied by hydrolysis of the triglyceride and reincorporation of the liberated fatty acid mainly into phospholipid. Where cholesterol suspension is injected together with the triglyceride emulsion the 14C‐labelled fatty acid is also incorporated into cholesterol ester in the nodes. Investigation by gas‐liquid chromatography of the labelled fatty acid in each of the lipid moieties in the nodes showed that some chain elongation of the 14C‐labelled palmitic acid occurred, but that the stearic acid formed appeared only in the phospholipid fraction.
RE‐EVALUATION OF RESPIRATORY REFLEXES
Authors: Paintal A. S.
Published: December 2014

In cats anæsthetized with chloralose it was found that below about 18° C. the rhythmic pattern of discharge in low‐threshold pulmonary stretch fibres is reversed in relation to the respiratory cycle. This reversed pattern is apparently responsible for the reversal of the Hering Breuer inflation reflex (Head's paradoxical reflex). Evidence favouring this is that reflex inhibition of respiration, produced by high frequency electrical stimulation of pulmonary stretch fibres applied against a background of low frequency stimulation, is converted to excitation between 9 and 11° C. Head's paradoxical reflex appears when the total discharge in low‐ and higher‐threshold pulmonary fibres during inflation becomes less than the total discharge in the former before inflation. A nomogram showing the relation between temperature and the peak frequency of a train of impulses in fibres of different conduction velocities is presented. The likely mechanism responsible for the quantitative variation of the inflation reflex (and its reversal) with temperature is given.
BALANCES OF WATER AND SODIUM IN THE RUMEN DURING FEEDING: OSMOTIC STIMULATION OF SODIUM ABSORPTION IN THE SHEEP
Authors: Stacy B. D. , Warner A. C. I.
Published: December 2014

When sheep ate a dry ration containing added sodium chloride the concentration of sodium in the rumen liquor did not increase. When solutions containing amounts of sodium similar to those eaten with the feed were administered via rumen fistulæ to fasting sheep, they caused a rise in sodium concentration that was sustained for at least 4 hr. Different results were obtained when the same dose of sodium chloride was given to sheep in which the rumen contents were made hypertonic by the addition of other solutes (potassium chloride or mannitol‐urea). Instead of rising, the sodium concentration fell 4 hr. after treatment.

Changes in the water content of the rumen were traced with a soluble marker, the 51Cr complex of ethylenediaminetetra‐acetic acid. After feeding, but not after solute administration, there was clear‐cut evidence of increased entry of body water into the rumen, the dilution rate increasing from 0·07–0·11 hr.‐1 to 0·19–0·28 hr.‐1. Total salivary secretion was measured in an animal with an œsophageal fistula and the results indicated that the increased water entry into the rumen was due to stimulation of saliva production on feeding.

By making several assumptions, sodium and water balances in the rumen were derived from the experimental data. In the fasting state the calculated sodium absorption was 6–16 m. equiv/ hr.; over the 2 hr. period after feeding or solute administration the value was 36–62 m.equiv/hr.

It was concluded that hypertonic conditions, as foumd after feeding or solute loading, stimulate the absorption of sodium from the rumen. The physiological implications of the findings are discussed in terms of the sheep's response to the diversion of sodium and water into the rumen on feeding.
EFFECTS OF ATROPINE TREATMENT ON THE SUBMAXILLARY GLAND OF RATS
Authors: Ohlin P. , Perec C.
Published: December 2014

The effects of atropine treatment on the rat's submaxillary gland were studied and compared with those of surgical parasympathetic denervation. In one day both procedures increase the weight of the gland. This gain in size of the gland is likely to be due to the secretory inactivity. In one week the effects of atropine and of surgical denervation on gland weight differ from one another. The gland weight is decreased after nerve section but not after atropine. In other respects the longterm action of atropine is similar to that of parasympathetic denervation: both procedures cause a supersensitivity to secretory agents and a decreased activity of respiratory enzymes.
THE NODE OF RANVIER IN THE CENTRAL NERVOUS SYSTEM
Authors: Peters Alan
Published: December 2014

The axolemma of myelinated nerve fibres of the central nervous system has been examined both at nodes and in the paranodal region. In the paranodal region, the outside of the axolemma is separated from the outer surface of the plasma membrane bounding the inner aspect of the paranodal cytoplasm by a distance of only 25–30 A, so that the two membranes form a complex. In longitudinal sections, a periodicity may be observed within this complex. It has been shown that this is mainly due to the form of the outer dense layer of the axolemma, which is modified into a series of bands or rings that circumscribe the axon. Each band is 120–150 A wide and the centre to centre spacing is 250–300 A. At the node, the axolemma does not show a periodicity and is not covered by a myelin sheath, but in the axoplasm beneath it there is a layer of osmiophilic granular material, about 250 A thick.
CHANGES IN SODIUM REQUIREMENT OF THE SHEEP ASSOCIATED WITH CHANGES OF DIET
Authors: Scott D. , Bruce J. B. , Dobson A.
Published: December 2014

Observations were made on 3 sheep while their rations were changed from dried grass cubes to fresh frozen grass, then to a dry diet of hay and meals and finally back to fresh frozen grass. In spite of the low sodium intake on the fresh grass, the sheep were neither losing nor gaining sodium up to the time the change to hay and meals was made. When hay and meals were given, the excretion of sodium in the urine fell to very low levels, and the composition of the saliva changed as if aldosterone secretion were increased. Since the hay and meals ration had the highest sodium content, a net retention of sodium was observed. This retention, accompanied by an increase in liveweight, appeared to be due to a sequestration of sodium and water within the rumen. On returning to the grass ration the sodium retained during the period when hay and meals were given was rapidly lost in the urine with a corresponding fall in the liveweight. The transient changes in sodium requirement associated with certain dietary changes thus appeared to reflect changes in the amount of sodium in the rumen. Less potassium tended to be retained during the period when hay and meals were given, but more was retained when the final ration of grass was begun; these changes were smaller than the changes in sodium balance. A transient mild hypomagnesaemia accompanied an initial period of magnesium loss both times that grass feeding began, with recovery of the concentration of magnesium in the plasma during the diet of hay and meals. We wish to thank Professor A. T. Phillipson and Dr. K. B. Blaxter for advice and criticism of the manuscript. Appreciation is also offered to Mr. J. Ingram and Mr. W. Fettes for skilled technical assistance during the course of these experiments. We also wish to thank Dr. F. Raymond, Grassland Research Institute, Hurley for advice on the cutting and storing of the frozen herbage.
THE WATER EXCHANGE AND POLYURIA OF RATS DEPRIVED OF FOOD
Authors: Morrison S. D. , Mackay C. , Hurlbrink Eleanor , Wier Jane K. , Nick M. Susan , Millar Florence K.
Published: December 2014

Male and female rats void a greatly increased volume of dilute urine for the first 1 or 2 days of deprivation of food with water allowed. The polyuria is not dependent on an increase of water intake and occurs unless intake falls to about 5 g./day. The polyuria also occurs when food intake is restricted to 1/3 normal but not on restriction to 2/3. Almost 2/3 of the excess urine not attributable to increased water intake could be accounted for as water absorbed from diminishing gut contents; the remainder may be derived from depletion of other labile pools of body water. The volume of urine can be restored to control levels and the concentration partially restored by simultaneous deprivation of food and water or by treatment with ‘Pitressin’. On more prolonged deprivation of food with water allowed, urine concentration approached control levels by day 4–6. On prolonged restriction of food, water turnover remained high and urine remained dilute for at least 6 days; concentration could be restored by ‘Pitressin’. It is concluded that the dilute urine of food deprivation and restriction is the result of a self‐imposed water diuresis. The high water turnover represents, by the criterion of the potential concentrating ability of the kidney, an inefficiency of water regulation.
QUANTITATIVE ASPECTS OF THE RECIRCULATION OF LYMPHOCYTES; AN ANALYSIS OF DATA FROM EXPERIMENTS ON SHEEP
Authors: Hall J. G.
Published: December 2014

By cannulating the efferent ducts of each of twenty popliteal lymph nodes in merino ewes it was possible to collect the lymph and thus measure the outputs of lymphocytes from these nodes for periods of over 100 hr., under physiological conditions.

A linear correlation between the weight of a lymph node and its output of lymphocytes was demonstrated. Although the statistical significance of this correlation was low, predictions based upon it agreed with the observed results of other investigations. It was therefore concluded that on average, in adult sheep, a lymph node weighing 1 g. discharges 30 million lymphocytes/hr. into the efferent lymph. It was shown that lymphocytes from the afferent lymph and de novo production within the node make only a small contribution to this number. Most of the lymphocytes in the efferent lymph must be supplied therefore directly from the blood which flows through the node.

Measurements of the venous outflow from individual prefemoral nodes in anæsthetized Clun Forest sheep showed that the blood flow through lymph nodes is of the order of 1 ml./min./g. node wt. Using this value it was calculated that some 12 per cent of the lymphocytes in the blood flowing through a node must leave the blood, pass through the substance of the node and enter the efferent lymph.
THE RELATIONSHIP BETWEEN CHANGES IN SERUM LEVELS OF GROWTH HORMONE AND MOBILIZATION OF FAT DURING EXERCISE IN MAN
Authors: Hartog M. , Havel R. J. , Copinschi G. , Earll J. M. , Ritchie B. C.
Published: December 2014

Mobilization of fat into the blood, evidenced by increased plasma levels of glycerol, was detectable 5–10 min. after healthy men in the post‐absorptive state began to exercise on a bicycle ergometer at a work load of 400 Kgm./min. Plasma levels of immunoreactive human growth hormone (IRHGH) did not change until after 20 min. of exercise, rose rapidly until 60 min. and then began to fall. No detectable fall in plasma level of glucose preceded the rise in IRHGH. These results are incompatible with a major role for growth hormone in mobilization of fat during such exercise. When subjects were given nicotinic acid before exercising, fat mobilization was blocked, but the pattern of increase in levels of IRHGH was not altered during the first hr. of exercise. IRHGH levels continued to increase until exercise was stopped and then fell more slowly than in control subjects. The rise in IRHGH during exercise does not, therefore, depend upon prior mobilization of fat, but such mobilization may inhibit its continued secretion.
OBSERVATIONS ON THE MICROCIRCULATION IN THE RABBIT EAR CHAMBER
Authors: Stehbens W. E.
Published: December 2014

Observations on flow patterns and platelet behaviour at vascular forks have been made in small blood vessels of rabbit ear chambers. At vascular forks and junctions, localized variation in the width of the marginal plasma zone has been noted corresponding to areas at which intimal thickening is known to occur in distributing arteries.

Platelet sticking and the formation of microthrombi did not tend to favour vascular forks or junctions. Observations did not indicate that eddy currents predisposed platelets to stick or to form thrombi.
THYROGLOBULIN IN THE LYMPH DRAINING FROM THE THYROID GLAND AND IN THE PERIPHERAL BLOOD OF RATS
Authors: Daniel P. M. , Pratt O. E. , Roitt I. M. , Torrigiani G.
Published: December 2014

It has previously been thought that organic iodine leaves the thyroid gland only in the form of iodoamino acids which are derived from the breakdown by the thyroid cells of the thyroglobulin stored in the colloid. It has now been shown that a considerable amount of iodoprotein also leaves the thyroid gland in the thyroid lymph and that most, if not all, of this iodoprotein is actually thyroglobulin. The iodoprotein in the thyroid lymph was studied by two different techniques, either by chemical separation of iodoprotein after giving the rats relatively small doses of 125I‐inorganic iodide or by measuring the amount of thyroglobulin by an immunoassay, which avoided the necessity of giving the animals radioactive iodine in vivo.

The iodoprotein content of the thyroid lymph is raised sharply by giving the rats thyroid stimulating hormone and also by thyroid massage which expresses the lymph contained within the lymphatics of the thyroid gland. Iodoprotein is virtually absent from peripheral lymph (i.e. lymph not containing any thyroid lymph). The peripheral blood of rats also contains small but appreciable amounts of thyroglobulin.

The implications of the presence of thyroglobulin outside the thyroid gland are discussed.
A METHOD FOR COLLECTING LYMPH FROM THE PREFEMORAL LYMPH NODE OF UNANAESTHET1SED SHEEP
Authors: Hall J. G.
Published: December 2014

A method is described for cannulating the efferent duct of the prefemoral lymph node in sheep so that lymph can be collected, if necessary for periods of weeks, under physiological conditions. By this means lymph was collected from 100 preparations; on average, the lymph flowed at a rate of 5 ml. per hr. and, after antigenic stimulation of the node, contained 50,000 lymphoid cells per c.mm. The method is suitable for British breeds of sheep kept in ordinary pens and the surgical procedure is simple.
EFFECT OF ENVIRONMENTAL TEMPERATURE ON THE CLOSURE OF FULL THICKNESS SKIN WOUNDS IN THE RAT
Authors: Cuthbertson D. P. , Tilstone W. J.
Published: December 2014

Full thickness skin wounds in hooded Lister rats of the Rowett Institute strain kept at an environmental temperature of 30° C closed more rapidly than did those in similarly wounded rats housed at 20° C. The differences were statistically significant. This response was exhibited by both sexes and was found in experiments carried out at both Aberdeen and Glasgow.

The wounds in male rats were found to close more rapidly than those in female rats housed at the same temperature. The rectal temperature of the animals was not affected by the environmental temperature but the temperature of wounded skin was significantly higher (ca. 0.9° C) in the animals held at 30° C. Also in these latter rats, the response of skin temperature at the wound margin differed markedly from those at 20° C.

Rats at 20° C pair fed to rats at 30° C, who even prior to wounding eat less than those at 20° C, did not respond differently from rats allowed food ad libitum at the lower temperature.

The epithelium of the wounds advanced at a linear rate in the final stages of closure.
POTENTIATION BY AMINOGUANIDINE OF THE SENSITIVITY OF SHEEP TO HISTAMINE GIVEN BY MOUTH. EFFECT OF AMINOGUANIDINE ON THE URINARY EXCRETION OF ENDOGENOUS HISTAMINE
Authors: Sjaastad Ö. V.
Published: December 2014

The sensitivity of sheep to orally administered histamine was greatly increased by aminoguanidine, a substance which inhibits histaminase (diamine oxidase, E.C. 1.4.3.6.). The increment in urinary free histamine after giving histamine by mouth (1·0–10·0 g. histamine diphosphate) was about 22 times larger in aminoguanidine‐treated sheep than in untreated ones. Furthermore, toxic manifestations were observed when 1 g. of histamine diphosphate or more was given to aminoguanidine‐treated sheep, whereas doses as high as 10 g. only had a slight effect on untreated animals.

When aminoguanidine was given, and oxidative deamination thus largely prevented, methylation of histamine seemed to increase.

Aminoguanidine increased the urinary excretion of endogenous free histamine on average by a factor of about 12. The above mentioned results indicate that oxidative deamination of histamine is more important in sheep than in species previously examined.
REINNERVATION OF SUBMAXILLARY GLANDS AFTER PARTIAL POSTGANGLIONIC DENERVATION
Authors: Emmelin N. , Perec C.
Published: December 2014

Supersensitivity following section of the chorda tympani within the hilum of the submaxillary gland of the cat, producing decentralization and partial postganglionic denervation, was found not to diminish during six months provided that preganglionic regeneration was prevented. When this was allowed to occur there was a very marked reduction of the sensitivity, a pronounced increase of the choline acetyltransferase activity, a lively secretion in response to chorda stimulation: the secretory responses to eserine injected into the gland through the salivary duct, which were very small shortly after the operation, increased in spite of decreasing sensitivity. These observations are taken as evidence that collateral regeneration occurred from the remaining postganglionic neurones but only when contact with the central nervous system had been re‐established by preganglionic regeneration.
PRESSURE MEASUREMENTS IN THE LESSER CIRCULATION OF THE NEWBORN RABBIT
Authors: Dennis Jennifer
Published: December 2014

An attempt is described to investigate whether some of the physiological responses of the pulmonary vascular bed in anæsthetized rabbits aged 0–31 days differ from those observed in other species, and it is shown that accurate measurements of phasic right ventricular pressure can be made in small animals with high heart rates using standard equipment.

A constant relationship of resting peak right ventricular to mean pulmonary arterial pressure is demonstrated in the resting state, but there are indications that the quantitative relationship changes with the circumstances. The variation with age of systemic and peak right ventricular pressure is shown; the latter changes are different from those described in other species and together with results obtained during hypoxia and asphyxia provide indirect evidence of ductus arteriosus closure on day 3. Pulmonary vascular pressor responses comparable to those of other species are never seen in the first 3 weeks and the fall in systemic pressure in response to asphyxia in very young animals is not due to coincident intense pulmonary vasoconstriction but could be explained by hypoxic dilatation of a patent ductus. A systemic response to hypoxia opposite to that to asphyxia is observed in rabbits older than 4 days. There is no evidence that intravenous infusion of acetylcholine in well‐oxygenated or hypoxic newborn rabbits has any direct effect on the pulmonary vascular bed.
A COMPARISON BETWEEN THE INHIBITORY EFFECT OF PERCHLORATE ON IODIDE AND PERTECHNETATE CONCENTRATIONS IN SALIVA IN MAN
Authors: Harden R. McG. , Alexander W. D. , Shimmins J. , Robertson J. W. K.
Published: December 2014

The inhibitory effect of the perchlorate ion on the concentration of iodide and pertechnetate has been studied in human parotid saliva, collected under resting conditions and during stimulation. The saliva/plasma (S/P) 132I and 99mTcO4‐ ratios and the salivary I and TcO4‐ clearances fell after perchlorate administration. The percentage fall in the S/P ratios was greatest under resting conditions.

The effect of increasing doses of perchlorate on the S/P I and TcO4‐ ratios was studied. There was a linear inverse relation between the S/P ratios and log. dose of perchlorate at perchlorate doses of 3 mM/day and greater. I‐ and TcO4‐ are not inhibited to the same extent by perchlorate. The ratio of the salivary I‐ to TcO4‐ clearance, measured simultaneously, was higher after perchlorate administration. The dose of perchlorate corresponding to inhibition of the S/P TcO4‐ ratio to half the control value was less than the dose required for a corresponding decrease in the S/P I‐ ratio.

The dose of perchlorate required to depress the S/P I‐ and TcO4‐ ratios to 50 per cent of the control value and to an absolute value of 0·5 was compared to the dose of iodide required to produce similar falls. It was concluded that perchlorate is a more potent inhibitor of the salivary iodide concentrating mechanism than iodide given in molal equivalent doses. Iodide, however, in contrast to perchlorate, depressed the S/P I‐ and TcO4‐ ratios to the same extent. Although TcO4‐ shares with I‐ one common transport mechanism, there are also differences in the transport of the ions from the blood into the saliva.
AFFERENT PATHWAYS AND EFFERENT MECHANISMS IN THE BLADDER VISCERO‐VASCULAR REFLEX
Authors: Taylor D. E. M.
Published: December 2014

The afferent and efferent limbs of the bladder viscero‐vascular reflex have been studied in cats under chloralose anæsthesia. The maximum change in arterial blood pressure in response to applied tension was obtained from the region of the trigone and bladder neck; lesser responses were obtained from all other regions of the bladder. The response to rapid bladder filling was little affectecd by hypogastric nerve section. Although it was much reduced after section of sacral posterior roots, it was not abolished until higher posterior roots had also been cut, sometimes Up to T 10.

In the presence of an intact nervous system, during the early stages of slow bladder filling hind limb vasoconstriction occurred, but there was compensatory limb vasodilation and bradycardia so that no change in blood pressure occurred. Later in the course of filling changes in blood pressure occurred and were associated with vasoconstriction in fore as well as hind limbs and subsequently tachycardia. Occasionally with extreme distension cardiac arrhythmias, such as ventricular or nodlal extra systoles, appeared. There was less compensation when filling was faster, and no compensation after baroreceptor denervation. Cardiac denervation abolished the changes in heart rate, but the circulatory changes in the limbs were unaffected.

It is concluded that bladder viscero‐vascular reflexes are initiated mainly by tension changes in the region of the trigone and bladder neck; the afferent path can be either the hypogastric or pelvic splanchnic nerves, although the predominant route is the latter; and in the presence of intact baroreceptor reflexes, changes in the circulation occur early and before any alteration in the arterial blood pressure.
SOME EFFECTS OF l‐HYOSCINE HYDROBROMIDE ON POST‐ROTATORY SENSATION AND NYSTAGMUS IN MAN
Authors: Benson A. J. , Brand J. J.
Published: December 2014

In a balanced double‐blind trial six subjects were given, on three successive days, an injection of 0·3 mg. or 0·6 mg. of l‐hyoscine hydrobromide or normal saline, 30 min. before rotational tests of vestibular function were performed. Hyoscine caused a significant (P = 0·01) depression of the ‘slope’ of the sensation cupulogram without alteration of the extrapolated ‘threshold’. This effect was not significantly greater with the higher dose of the drug. In subjects who had received hyoscine there was an appreciable suppression of the post‐rotational nystagmic response, and slow pendular oscillations of the eyes were frequently recorded. These effects were antagonized by mental arithmetic.

It was concluded that hyoscine increased adaptation in the vestibular sensory system and released the oculomotor system from the ascending influence of vestibular and reticular projections.
THE ULTRASTRUCTURE OF THE EJACULATED FOWL SPERMATOZOON
Authors: Lake P. E. , Smith W. , Young D.
Published: December 2014

The ultrastructure of the fowl spermatozoon differs in several ways from that of the mammalian spermatozoon, and the probable implications of the findings for the difficult problem of storing fowl semen in vitro are discussed. The acrosome has a simpler structure than in the mammal and does not spread down over the membrane of the head. Greater structural differences occur in the tail region, the middle‐piece of which is particularly prone to deteriorate in vitro. The eleven axial (tail) fibres arise from a centriolar complex in the neck region of the spermatozoon; at this level, and more distally in the wall of the distal centriole, they resemble microtubules in cross‐section. The nine outer ones show the triplet tubule structure typical of cell centrioles. The complex ‘endoskeleton’ of segmented columns in the neck, and outermost coarse fibres in the middle‐piece and principal‐piece of the tail, are absent in the fowl. In the distal part of the middle‐piece the tail fibres separate; here and in the principal‐piece they show the typical doublet structure seen in the tail of mammalian spermatozoa, cilia and flagella. The principal‐piece of the fowl spermatozoon is composed solely of a continuous sheath of amorphous material surrounding the eleven axial fibres; the sheath is absent from the distal end of the tail. In contrast with the situation in the mammal, no segmentation of this material is evident and no continuous lateral columns are present in the tail.
THE EFFECT ON BLOOD AND URINE OF THE INGESTION OF SODIUM BICARBONATE
Authors: Matthews D. L. , O'Connor W. J.
Published: December 2014

O·145M NaHCO3 given by stomach tube to conscious dogs caused a fall in plasma solids (protein), decrease in plasma Cl and increase in HCO3; pH of the arterial blood increased but any increase of arterial PCO2, was not significant; plasma K fell. The urine after 0·145M NaHCO3 contained increased amounts of Na with only a small increase in Cl. The increased excretion of Na+ was mainly accompanied by a large excretion of HCO3‐, and the urine became alkaline and contained little NH4+. Changes in the excretion of inorganic PO4, SO4 and K were small.

Comparison was made with the effects of the same doses of Na given as 0·122M NaCl+0·023M NaHCO3. This caused an equal fall in plasma solids but no change in plasma Cl, HCO3 and K. The urinary excretion of Na+ increased to rates approximately the same as those produced by NaHCO3 but the main urinary anion was Cl‐, the excretion of which was greatly increased. There was a small excretion of HCO3‐ with larger doses.

It is concluded that an important agent determining increased excretion of Na is dilution of the plasma protein, which is common to both types of experiment. The changes in plasma Cl and HCO3 appear to be the factor which determines whether the increased excretion of Na+ is accompanied mainly by HCO3‐ or Cl‐.
THE EFFECTS OF CORTISONE AND SOMATOTROPHIN ON BONE GROWTH IN RATS
Authors: Raman A.
Published: December 2014

The effects of cortisone and growth hormone on bone growth in rats were determined by the use of the tetracycline staining technique. The results obtained showed that both cortisone and growth hormone in a dosage of 20 mg./kg. body weight significantly affected appositional growth rate as well as total bone formation rate (p 〈 0·001). Growth hormone produced increased bone formation, but cortisone depressed bone formation.
THE EFFECTS OF INTRAVENOUS INFUSION OF KCl OR HCl ON THE RENAL EXCRETION OF POTASSIUM IN SHEEP
Authors: Scott D.
Published: December 2014

Intravenous infusion of potassium chloride in sheep led to a rise in the concentration of potassium in the plasma, and to an increase in the rate of excretion of potassium in the urine, which rose rapidly until the rate of excretion of potassium was about equal to the rate of infusion of potassium. During potassium infusion the rate of excretion of potassium in the urine in some experiments exceeded the rate of filtration of potassium across the glomerulus, indicating net secretion of potassium by the renal tubules. Intravenous infusion of HCl did not modify the renal response to intravenous infusion of potassium, but only a small proportion of the acid infused appeared in the urine.

Chronic acidosis resulting from intra‐ruminal infusion of HCl led to an increase in the rate of net acid excreted but no change in the rate of excretion of potassium in the urine. A large proportion of the net acid excreted was in the form of the ammonium ion and little was present as titratable acid. This result suggests that the excretion of large amounts of potassium in the urine of the sheep may limit the rate of excretion of titratable acid.
GLUTAMINE METABOLISM IN THE PERFUSED RAT HEART
Authors: Ottaway J. H.
Published: December 2014

Changes in the concentration of glutamate, glutamine, alanine and aspartate have been measured during perfusion of isolated rat hearts. During a 60 min perfusion the concentration of glutamine fell by two‐thirds: the extent of the fall is consistent with hydrolysis by cardiac glutaminase. The concentrations of the other 3 amino acids did not change significantly in the heart, but alanine and aspartate, and to a less extent glutamate, accumulated in the perfusate in amounts equivalent to the glutamine which had disappeared.

When 10 µg./ml. bovine growth hormone was added to the perfusate, the tissue glutamine level was slightly higher and about 1 µmole glutamine/g. heart/hour accumulated in the perfusate. The concentrations of the other amino acids, both in the heart and in the perfusate, remained essentially unchanged.

The significance of these results with respect to cardiac glutamine metabolism is discussed.
DISTRIBUTION AND FATE OF Mn54 IN THE RAT, WITH SPECIAL REFERENCE TO THE C.N.S
Authors: Dastur Darab K. , Manghani Daya K. , Raghavendran K. V. , Jeejeebhoy K. N.
Published: December 2014

In view of the still prevalent problem, in certain mining communities, of chronic manganese toxicity affecting the C.N.S., and the paucity of experimental data explaining the mechanism of this, the distribution and fate of isotopic Mn54 in different organs and tissues and in the whole body of the rat was studied over a period from 15 min to 34 days after intraperitoneal injection of an Mn54 maleate solution.

While the curve for the whole body and for most organs could be resolved into two exponential components, the slower component was not present for the C.N.S. The blood seemed to serve as a transport medium receiving and discharging the Mn54 rapidly. While most organs showed a gradual decline with time in the counts per minute per gram of tissue and in the retained dose, the brain and the spinal cord exhibited a steady rise from the beginning to end. The suprarenal, pituitary, heart and bone also evidenced this to some extent. A greater capacity for relative retention of a small dose of manganese by the C.N.S. might be responsible for its selective vulnerability in chronic manganism.
POST‐OCCLUSION ‘HYPEREMIA’: A STUDY ON A MODEL
Authors: Rodbard Simon , Takeda Yoshiyuki , Takacs Lajos
Published: December 2014

The hydrodynamic properties of the capillaron, i.e. a compliant capsule which encloses one or more soft‐walled permeable capillaries together with extravascular fluid, can account for the known characteristics of reactive hyperemia. This has been demonstrated in a model of the capillaron. A constant arterial pressure head delivered fluid to the enclosed capillary and thence to a venous sink. The flow rate varied with the perfusion pressure and with the calibre of the soft‐walled vessel. Vascular calibre depended on the transmural capillary pressure. A positive pressure opens the capillary completely and the flow rate for the perfusion pressure is maximal. Capillary permeability results in ‘ultrafiltration’ which raises the extravascular pressure, thereby lowering the transmural pressure, until the capillary is partially collapsed. In the ‘resting’ or basal state, the flow rate through the capillaron is only a small percentage of the maximal flow through the system. Occlusion of the arterial supply is followed by drainage of extravascular fluid across the permeable membrane and tissue pressure falls progressively with the duration of the occlusion. Reopening of the artery raises the intravascular pressure and the positive transmural pressure opens the capillary, with the result that flow approaches maximal values. The flow during the hyperemic phase is affected by the duration of occlusion, the arteriovenous perfusion pressure, the permeability of the capillary, and the compliance of the capsule.

The effects of these changes on transcapillary fluid exchanges are described. Several variations of the hyperemic manoeuvre, including the effects of arterial occlusion without hyperemia, hyperemia without occlusion, hypoemia, the inter‐ relationships between blood and ultrafiltrate flows, and the potential exchanges of diffusible and of filterable materials are demonstrated and shown to correspond to the findings in man and animals.
EXPOSURE TO HIGH ALTITUDE OF SHEEP WITH DIFFERENT HÆMOGLOBINS
Authors: Battaglia F. C. , Behrman R. E. , de Lannoy C. W. , Hathaway W. , Makowski E. L. , Meschia G. , Seeds A. E. , Schruefer J. J. P.
Published: December 2014

The O2 pressure, saturation and capacity, the pH and CO2 pressure in the arterial blood of nonanæsthetized sheep were measured at two altitudes (1600 and 4340 metres). At high altitude sheep carriers of A hæmoglobin had a mean arterial saturation significantly higher than the B hæmoglobin carriers (86·4 ± 0·6 vs. 67·5 ± 1·0). The carriers of a mixture of A and B hæmoglobins had an intermediate saturation: 77·0 ± 1·0. There was no significant difference among the three groups in arterial PO2, pH, PCO2, oxygen capacity and hæmatocrit.
ANOXIC AND SECRETORY VACUOLATION IN THE ACINAR CELLS OF THE PANCREAS
Authors: Tapp R. L.
Published: December 2014

Vacuoles, 2–20µ in diameter, develop in the acinar cells of the rat pancreas when small cubes (2mm3) of tissue are incubated for 1 hr at 20° C in unoxygenated media such as Tyrode's solution or rat's serum. For vacuolation to occur the cells must be anoxic and have access to excess fluid containing Ca2+ and either Na+ or Li+. The vacuoles are bounded by a membrane and develop from or near the Golgi complex. Vacuolation is prevented if the medium is cooled to 0° C, if 270 m‐osmoles of sucrose, glucose or glycerol is added to the medium, or if the essential cations are not available: it is not prevented by the addition of 270 m‐osmoles of urea or propylene glycol, by the addition of poisons which block oxidative phosphorylation or glycolysis, or by substituting Li+ for Na+. Vacuolation can be increased by allowing the tissue to stand at 20° C for 15 or 30 min before immersion in a suitable medium. It is suggested that vacuolation involves two distinct, passive movements of fluid, firstly from the external medium into the cytoplasmic matrix, and then from the matrix into the vacuoles. The second movement appears to involve the enzymic breakdown of large, precursor molecules in some part of the Golgi complex. Vacuolation was also induced by massive stimulation in vivo using a mixture of acetyl choline and eserine. It is suggested that anoxic vacuolation and secretory vacuolation share a common mechanism.
THE EFFECT OF EXOGENOUS OESTROGEN ON THE BLOOD FLOW AND OXYGEN CONSUMPTION OF THE UTERUS OF THE NON‐PREGNANT EWE
Authors: Huckabee W. E. , Crenshaw C. , Curet L. B. , Mann L. , Barron D. H.
Published: December 2014

Observations on unrestrained nonpregnant ewes, prepared with appropriately placed indwelling catheters for obtaining blood samples, indicate that the administration of oestrogen ‐ either I.M. or I.V. ‐ is followed by a fall in the coefficient of O2 utilization of the uterus, and an increase in the blood flow through it, that were often detectable 30 min later and approached minimum and maximum values respectively after about an hour and a half. Similar results were obtained in acute experiments at which the uterine blood flow was measured directly and the oxygen consumption (ml./kg/min) determined. In all of the acute experiments the blood flow increased after oestrogen administration in the absence of any regular increase in O2 consumption. In three experiments the flow rate (ml./kg/min) increased about fivefold.
ARGININE METABOLISM IN THE BLOOD CELLS OF CATTLE AND GOATS
Authors: Barej W. , Hill H.
Published: December 2014

Active arginase was found in the cells of cattle blood, but not in those of goats. Blood cells of cows contained no arginine. When 14C arginine was incubated with the blood of cows, 14C ornithine could be detected in both cells and plasma. More arginine was found in the cells of goat blood than in the plasma. After incubation with 14C arginine, no 14C ornithine was found in goat blood. The possible role of blood cells in urea production is discussed.
THE INTRAVENOUS GLUCOSE TOLERANCE TEST IN THE PIG
Authors: Anderson D. M. , Elsley F. W. H.
Published: December 2014

After intravenous injection of 50 g glucose the blood glucose concentration in sows declined very quickly from the high concentrations initially found. The blood glucose concentration always returned to the fasting concentration within the period 18–45 min after glucose injection. The rate at which the glucose was removed was a function of the total blood glucose concentration.

After the blood glucose concentration returned to the fasting concentration, the concentration continued to fall, concentrations of 5–10 mg/100 ml. being achieved regularly with no overt signs of hypoglycaemia.

The time required for the blood glucose concentration to return to the fasting glucose concentration was found to be the most repeatable quantitative assessment of the test in the pig.
STUDY OF PREGNANCY KETOSIS IN THE RAT
Authors: Cheng Kwok‐Kew , Yang Mabel Mei‐Po
Published: December 2014

Fasting caused a significantly greater hyperketonaemia and hypoglycaemia in late pregnant rats than in non‐pregnant rats, and the hyperketonaemia after 1 day of fasting was greater in primiparous than in pregnant multiparous rats. In primiparous rats with hypertrophic adrenals produced by ACTH pretreatment, the degree of fasting ketosis was reduced to that in non‐treated pregnant multiparous rats. The adrenal weight of late pregnant rats was significantly heavier, and the adrenal gland of non‐pregnant multiparous rats was bigger than that of virgin rats but smaller than that of pregnant rats. Progesterone administration in virgin and adrenalectomized virgin rats caused greater fasting ketosis and less hypoglycaemia. Progesterone administration in pregnant rats caused toxaemic changes, and in pregnant multiparous rats a more severe fasting ketosis. Oestrogen administration in virgin rats increased the ketosis and decreased the hypoglycaemia after fasting. The present study indicates that increased fetal demands for glucose and increased endocrine activity contribute to metabolic changes which cause pregnancy ketosis.
THE IPSILATERAL RETINOTECTAL PATHWAY IN THE FROG
Authors: Keating M. J. , Gaze R. M.
Published: December 2014

The pathway from the retina to the ipsilateral optic tectum has been investigated by observing the effects of localized lesions on the electrical responses recorded from the superficial neuropil of the optic tectum in response to visual stimulation of the ipsilateral eye. The ipsilateral projection travels first to the contralateral tectum and then back by an intertectal link to the ipsilateral tectum. Destruction of the intertectal commissure, the posterior commissure and the deep tegmental commissures does not abolish the ipsilateral responses. After lesions of the post‐optic commissural system the ipsilateral tectal responses disappear.
BLOOD VOLUME CHANGES DURING PREGNANCY AND LACTATION OF SOWS
Authors: Anderson D. M. , Elsley F. W. H. , McDonald I.
Published: December 2014

Plasma volume and haematocrit were measured at approximately 20 days intervals in 3 gilts (sows in their first pregnancy and lactation) throughout pregnancy and in 2 of these gilts during lactation. Measurements were made at the beginning and end of pregnancy in a further 9 sows and also at mid‐pregnancy in 4 of these latter sows.

In the gilts PV declined during the first 40 days and then increased until parturition. In lactation the PV continued to rise during the first 14 days and then decreased steadily until weaning. Calculated RCV increased linearly during pregnancy and fell immediately after parturition.

The results obtained from the sows again showed only a sight rise in PV and RCV until day 70 and then a sharp rise until parturition. There was no relationship between the increase in PV and the weight of the litter born.
OPTIC NERVE FIBRE COUNTS AND RETINAL GANGLION CELL COUNTS DURING DEVELOPMENT OF XENOPUS LAEVIS (DAUDIN)
Authors: Wilson Margaret A.
Published: December 2014

An account is given of the development of the optic nerve in Xenopus laevis (Daudin). The stages studied were 35, 38, 46, 52, 58, immediately post‐metamorphosis (66), the juvenile of six months from metamorphosis and the adult. Fibre counts were made from complete electron micrograph montages for all the stages investigated including the adult. Corresponding ganglion cell counts were made from sections prepared by light microscopic histology from stage 46 upwards.

The large increase found in the ganglion cell population during development was also found in the optic nerve fibre counts. There was an approximate 1 : 1 relationship between the optic nerve fibres and the retinal ganglion cells.

The number of fibres increased from less than 1,000 (stage 35) to 59,000 (six‐month‐old juvenile). The older adult animal possessed fewer unmyelinated fibres than the six month old juvenile, but twice as many myelinated fibres, so producing a smaller total number. It seems that the process of myelination continues well into adult life.
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.