bluuebunny/crossref_metadata_2025 huggingface dataset:
Two decades of voluntary nonremunerated blood donation in Shenzhen, China
Authors: Yang Bao‐Cheng , Shao Chao‐Peng , Zhang Yan‐Yan , Kong Lingkui , Xu Yun‐Ping
Published: December 2014

Background

As an emerging metropolis with population expansion from 2 million to 10 million from 1993 to 2012, the clinical demand for blood in Shenzhen has increased 20 times. To deal with this big challenge, Shenzhen utilized voluntary nonremunerated blood donation (VNRBD) in 1993 for the first time in China. After two decades of efforts, Shenzhen has achieved self‐sufficiency in its blood supply and guaranteed its blood security by nonpaid blood donation.

Study Design and Methods

We summarized the strategies to achieve self‐sufficiency and security in the blood supply in Shenzhen during two decades, including the legal construction of VNRBDs and the continuously improving strategies to recruit and retain nonpaid donors. The collection data of whole blood (WB) and apheresis platelet (PLT) donations were retrieved, and donor demographic and donation characteristics were analyzed.

Results

From 1993 to 1998, paid and nonpaid blood donations coexisted in Shenzhen. From the year 1999, all WB for clinical use came from VNRBDs. From 1999 to 2012, the donors who chose to donate 400 mL each time and repeat and regular donors increased sharply to meet the fast growth of clinical demand. From the year 2005, the clinical demand for PLTs was entirely satisfied by nonpaid donations.

Conclusions

After two decades of practice, we believe that the legal regime of VNRBD is fundamental guarantee for long‐term self‐sufficiency and security in the blood supply. In addition, strengthening the publicity to improve the public's awareness and improving donation services and measures to recruit more nonpaid donors and retain repeat and regular donors are very important.
Effect of topical ophthalmic dorzolamide(2%)–timolol(0.5%) solution and ointment on intraocular pressure in normal horses
Authors: Tofflemire Kyle L. , Whitley Elizabeth M. , Flinn Allison M. , Dufour Valerie L. , Ben‐Shlomo Gil , Allbaugh Rachel A. , Griggs Angela N. , Peterson Chimene S. , Whitley David R.
Published: December 2014

Objective

To compare the effect of commercially available solution and compounded ointment formulations of dorzolamide(2%)–timolol(0.5%) on intraocular pressure (IOP) of normal horses.

Animals

Eighteen clinically normal horses.

Procedures

A randomized, masked prospective design was used with horses divided into two equal groups. One eye of each horse was selected for topical ophthalmic treatment with either 0.2 mL of dorzolamide(2%)–timolol(0.5%) solution or 0.2 g of dorzolamide(2%)–timolol(0.5%) ointment every 12 h for 5 days. The contralateral eye of horses in both groups was untreated. Rebound tonometry was performed every 6 h starting 2 days prior to and ending 2 days after the treatment period.

Results

The meanIOPreduction in eyes treated with the solution or ointment formulations was 13%. Untreated eyes in both groups experienced a lesser but still statistically significant reduction inIOP. TheIOPvalues did not return to baseline within 48 h of the last treatment.

Conclusions and Clinical Relevance

The commercially available solution and compounded ointment formulations of ophthalmic dorzolamide(2%)–timolol(0.5%) had similar effects onIOPin normal horses. PersistentIOPreduction following cessation of treatment may indicate prolonged drug effect or acclimation of horses to tonometry.
THE INFLUENCE OF VITAMIN E ON OVARIAN STRUCTURE IN MICE
Authors: Menschik Z.
Published: December 2014

A serial histological study has been made of the ovaries of mice fed from the day of weaning on several different diets, the principal being a vitamin E deficient diet and one containing alpha‐tocopherol (“Ephynal” Roche) as the only vitamin E source. Control animals were kept on stock diet, lettuce being the main source of vitamin E. Animals were examined after periods ranging from 7 to 791 days of the particular diet.

1. Animals on vitamin E rich diet, compared with controls, show ovaries with more primordial ova and primary follicles: follicular cells and interfollicular tissue of epithelial origin are more abundant, but degenerating follicles are numerous: there are fewer mature follicles and corpora lutea, both of which are enlarged. After prolonged vitamin E rich diet the ovary is small with degenerating follicles containing blood: neutral fat is present in the ovarian medulla and adipose tissue is extremely abundant in the mesovarium.

2. Animals on vitamin E deficient diet, compared with controls, show ovaries with fewer primordial ova and less interfollicular tissue: follicles contain fewer follicular cells: corpora lutea are increased, but are smaller and of various ages: medullary lipids, not readily soluble in fat solvents, are prominent, yet there is complete absence of neutral fat in both ovary and mesovarium. As the vitamin E deficiency continues, the lipids invade the ovarian cortex. After prolonged vitamin E deficient diet the ovary, comparatively large, is hard and yellowish and contains only cells filled with lipids other than neutral fat.

The ovarian changes summarised under 1 and 2 appear to be quantitative rather than qualitative; but it seems certain that vitamin E stimulates the development of all elements of germinal epithelium origin, and that it influences fat metabolism in the ovary and its neighbourhood so that neutral fat increases, while the formation of other lipids is inhibited.

I wish to express my deep gratitude to Professor J. C. Brash, Professor of Anatomy, University of Edinburgh, under whose supervision the experiments have been performed, for his continuous readiness in advising, for providing accommodation and material for experiments, and also for revising the manuscript. I am deeply thankful to Professor T. Rogalski, Professor of Anatomy, Polish School of Medicine, Edinburgh, for guidance, advice, and suggestions received from him. I am very much indebted to Messrs Roche Products Ltd., Welwyn Garden City, England, by whom the synthetic vitamin E was generously provided. I owe thanks also to Mr. J. Borthwick, Anatomy Department, University of Edinburgh, for photomicrographs, and to all members of the staff of the Anatomy and Embryology Department of the Polish School of Medicine, who always willingly gave me technical assistance.
The electroretinogram evoked by the excitation of human foveal cones
Authors: Aiba T. S. , Alpern M. , Maaseidvaag F.
Published: December 2014

1. A 2° test stimulus foveally fixed and viewed against a blue background (40° in extent and producing 2·0 × 104 scotopic td of retinal illuminance) evokes a small voltage which can be recorded from the human eye with a conventional contact lens electrode if the test stimulus is flashed at a rate of 15 c/s, and the responses to at least several hundred flashes are averaged.

2. The action spectrum of the response obtained in this way agrees reasonably well with the observer's psychophysical foveal luminosity curve.

3. For the peripheral retina, the action spectrum is similar to that of the fovea when allowance is made for differences in screening macular pigment.

4. Such responses diminish when the test stimulus is focused on to the peripheral retina and disappear when the test light is focused on the blind spot.

5. Therefore, the response to the test light fixated centrally is the result of the excitation only of cones mainly, if not exclusively, in the fovea.

6. When the intensity of the background is reduced by a factor of 10, the action spectrum shows evidence of the effect of excitation of rods in the blue part of the spectrum and of cones in the red. These red and blue responses add linearly when combined together, provided they are adjusted to coincide in phase.
Short latency activation of pyramidal tract cells by Group I afferent volleys in the cat
Authors: Swett John E. , Bourassa Charles M.
Published: December 2014

1. The contralateral bulbar pyramids were explored with low impedance micro‐electrodes in cats anaesthetized with chloralose to reveal the effect of Group I afferent volleys (deep radial nerve of the forelimb) on pyramidal tract (Pt) cells.

2. Low rate (0·5/sec) stimulation of Group I afferents produced small responses (5‐30 μV) in the bulbar pyramid which could be detected only with response averaging methods. The responses appeared with an initial latency of 7·0‐11·2 msec and reached peak amplitude in 15·7 msec (mean latency). The pyramidal tract origin of the potential was demonstrated by its depression at stimulus rates above 1–2 sec and its disappearance at rates above 4/sec.

3. Recordings of neurones in the Group I cortical projection zone of the posterior sigmoid gyrus revealed that several types of cells, including Pt cells, were activated by Group I afferent volleys.

4. Pt cells responding to Group I afferent volleys frequently received convergent actions from low threshold cutaneous nerve volleys.

5. Averaged response recordings from electrodes positioned in the medial portions of the lateral funiculus of the spinal cord at the level of C2, revealed a response to Group I afferent volleys as early as 7·4 msec which possessed the same characteristics as the relayed response to Group I in the bulbar pyramids. Some Pt cells, activated by Group I volleys orthodromically, could also be antidromically activated by stimulation of the recording site in C2.

6. It was concluded that group I afferent volleys can influence, after short latencies, Pt and non‐Pt cells and that some of these Pt cells gave rise to axons incorporated in the corticospinal tract.
The relation between heat produced and phosphorylcreatine split during isometric contraction of frog's muscle
Authors: Carlson F. D. , Hardy Donna , Wilkie D. R.
Published: December 2014

1. Heat production, tension development and phosphorylcreatine (PC) splitting have been measured simultaneously during isometric contractions of iodoacetate‐poisoned frogs' sartorii at 0° C. The muscles were stimulated to produce a series of 30 twitches or a 10 sec tetanus or a 30 sec tetanus.

2. Of the several possible methods of calculating PC breakdown the best appears to be the one based on the assumption that PC/(total creatine) was originally the same in the two muscles of a pair.

3. The difficulty of expressing PC break‐down, heat production etc. in terms of the muscle's size is demonstrated.

4. Several artifacts are discussed, including the heat produced by the stimulus and the possible role of reactions other than PC splitting.

5. Even when these have been substantially eliminated there remains the rather intractable statistical problem of establishing a functional relationship between heat produced and PC split when both of these variables contain errors, so that ordinary regression analysis is misleading. It is shown that this problem can be dealt with satisfactorily by introducing other instrumental variables that can be determined experimentally.

6. The final conclusion is that the in vivo enthalpy of hydrolysis of PC is about 10·6 kcal/mole, and is the same in twitches and in tetani.
The mechanism of body temperature changes induced by intraventricular injections of adrenaline, noradrenaline and 5‐hydroxytryptamine in the ox (bos taurus)
Authors: Findlay J. D. , Robertshaw D.
Published: December 2014

1. Adrenaline, noradrenaline and 5‐hydroxytryptamine (5‐HT) were injected into the lateral ventricle of the ox. The effect of these drugs was measured on the respiratory rate, tidal volume, heat production, skin temperature of the ear, evaporative loss from the skin and the rectal temperature at 20 and 10° C ambient temperature.

2. Neither adrenaline (3 mg) nor noradrenaline (3 mg) had any effect on the temperature regulating mechanisms of the ox, except to produce vasoconstriction if vasodilatation was already present due to high ambient temperature or previous injection of 5‐HT.

3. Injection of 5‐HT (5 mg) caused a rise in respiratory rate, a fall in tidal volume and heat production, elevation of ear skin temperature and skin evaporative loss and a decrease in rectal temperature. Sedation of the animals occurred.

4. In its reaction to these monoamines the ox is similar to the goat, sheep and rabbit, but is unlike the cat and dog.

5. It was concluded that neither adrenaline nor noradrenaline has a role in the central control of temperature regulation in the ox, but that 5‐HT may be involved in the control of heat dissipation mechanisms.
The effects of haemorrhage in the unanaesthetized rabbit
Authors: Chalmers J. P. , Korner P. I. , White S. W.
Published: December 2014

1. The circulatory response following acute loss of 26% of the blood volume was examined in unanaesthetized rabbits. The groups of animals studied were normal rabbits; adrenalectomized rabbits; animals subjected to prolonged treatment with guanethidine in which peripheral adrenergic nerve transmission is blocked, but which can reflexly liberate adrenal medullary hormones; animals subjected to combined adrenalectomy and guanethidine treatment with no functional adrenergic effectors; in each case with or without administration of atropine. The responses of animals with section of the carotid sinus and aortic nerves were also examined.

2. The spontaneous rate of replacement of the blood volume after haemorrhage by reabsorption of extravascular fluid was the same in all the above preparations, the blood volume returning to normal 3‐4 hr after bleeding.

3. The ‘passive’ effects of haemorrhage were examined in animals without functioning autonomic effectors and include a large fall in right atrial pressure and cardiac output, arterial hypotension, no significant change in total peripheral resistance, and a bradycardia of gradual onset. Reflex autonomic effector activity in normal animals minimizes the fall in atrial pressure, cardiac output and arterial blood pressure, and produces a significant increase in total peripheral resistance and tachycardia. Increased sympathetic nerve activity and secretion of adrenal medullary hormones each play an important and complementary part in the normal circulatory response to haemorrhage of the rabbit. There is also reflex reduction in vagal efferent activity.

4. Reflexes from the carotid sinus and aortic arch limit the fall in arterial pressure for the first 4 hr after haemorrhage. These reflexes also account for the tachycardia normally observed after haemorrhage. The baroreceptor reflexes rather than the chemoreceptors appear to be dominant in these responses.

5. Twenty‐four hours after haemorrhage the haemodynamic pattern is similar in all preparations irrespective of their autonomic effector status: blood volume, right atrial pressures and cardiac outputs are all elevated, and the arterial pressure has virtually recovered, consistent with the development of hypervolaemic anaemia at this time.
The effect of pH on the 36Cl efflux from frog skeletal muscle
Authors: Hutter O. F. , Warner Anne E.
Published: December 2014

1. Frog sartorii and toe muscles were loaded in a 100 m
M‐K 216 m
M‐Cl solution at pH 7·4 labelled with either 36Cl, or 42K, or with both isotopes. The efflux of the isotopes into inactive solution of the same composition at pH 5·0 and 9·8 was followed.

2. The efflux of 36Cl into acid solution was extremely slow so that the cellular fraction could easily be distinguished. On raising the pH the efflux of 36Cl from sartorii increased 4·5 ± 0·43 (mean ±
S.E.) times; from toe muscles 6·7 ± 0·69 (mean ±
S.E.) times. The effect was fully reversible.

3. The efflux of 42K from sartorii was only slightly increased by alkaline solutions. When the effluxes of 36Cl and 42K were measured simultaneously the increment in chloride efflux was much greater than the increment in 42K efflux.

4. Toe muscles depolarized by high potassium solution showed an approximately twofold increase in 42K efflux on transfer from acid to alkaline solution. This effect was independent of the presence of chloride ions.

5. The results confirm the identification of chloride as the ion species principally concerned in the pH sensitivity of the membrane conductance.
Potentiation of secretin stimulation of the pancreas
Authors: Brown J. C. , Harper A. A. , Scratcherd T.
Published: December 2014

1. In fasted anaesthetized cats which were secreting pancreatic juice at a steady slow rate in response to continuous intravenous infusion of secretin, stimulation of the dorsal vagus trunk increased the rate of secretion, the rate of output of amylase and the concentration of bicarbonate in the juice.

2. The increase in rate of secretion and in concentration of bicarbonate was reduced but not abolished by atropine. It was unaffected by adrenergic blocking agents, but abolished by hexamethonium.

3. No increase in rate of secretion of secretin‐stimulated juice was observed on cervical stimulation of vagus nerves in which the efferent fibres had degenerated after supra‐nodose section of the nerves. It is concluded that the increase in secretion rate is mediated by ‘atropine‐resistant’ efferent vagal fibres.

4. Pancreozymin, antral extracts and histamine increased the rate of secretion of secretin‐stimulated juice. Pancreozymin and antral extracts also increased the rate of amylase output. These effects of pancreozymin and antral extracts were not abolished by atropine or hexamethonium.

5. As vagal stimulation pancreozymin, antral extracts and histamine have little or no effect on the resting pancreas of the anaesthetized cat, it is concluded that they exert a potentiating effect on secretin. It is suggested that the mechanism of this potentiation is an increase in pancreatic blood flow, which facilitates the supply of secretin to the gland.
The metabolic response of brain slices to agents affecting the sodium pump
Authors: Ruščák M. , Whittam R.
Published: December 2014

1. Slices of brain cortex from rabbits were incubated in Ringer solution and in Ringer modified by the removal of calcium and sodium, and the addition of ouabain, oligomycin or extra potassium. The potassium content of the tissue, the oxygen consumption and the lactate production from glucose were measured and found to be interrelated.

2. Incubation in high‐K Ringer caused an increase in oxygen consumption that was prevented by ouabain, oligomycin and deprivation of sodium. Lactate production was also raised, but this increase was unaffected by ouabain and raised further by oligomycin.

3. Calcium omission raised metabolism; the tissue K content was unaffected. Oligomycin always decreased oxygen consumption and raised lactate production further. The metabolic responses to calcium, potassium, ouabain and oligomycin depended on sodium.

4. After anaerobic incubation, the tissue potassium concentration was still 5 times higher than that in Ringer. It was unaffected by oligomycin but lowered markedly by ouabain.

5. The synergistic effects of sodium with potassium, oligomycin, calcium, and calcium plus ouabain suggest that the metabolic responses of brain cortex slices to a high‐K Ringer depend on the operation of the sodium pump.
Anion permeability of the inhibitory post‐synaptic membrane of the crayfish neuromuscular junction
Authors: Takeuchi A. , Takeuchi Noriko
Published: December 2014

1. The membrane conductance of the crayfish muscle fibre was calculated and the increase in the membrane conductance brought about by the application of γ‐aminobutyric acid (GABA) was investigated under various conditions. The permeability of the activated inhibitory post‐synaptic membrane was estimated from the conductance change.

2. When the concentration of Cl− was changed by substituting Cl− with methylsulphate, a linear relation was obtained between the membrane conductance change produced by GABA and the concentration of Cl−. Cations have no appreciable effect on the GABA induced conductance change (less than 0·4%).

3. The conductance change produced by GABA on the inhibitory post‐synaptic membrane was measured in various solutions in which the Cl− was replaced by various anions. The degree of permeability depended on the anion species in the following order:

Br− > Cl− > SCN− > I− > NO3− > HCOO− > ClO3− > ClO4− > BrO3−

4. At high pH the conductance change produced by GABA was decreased, while at low pH it increased.

5. These results show that the activated inhibitory post‐synaptic membrane of crayfish muscle fibres has the characteristics of an anion selective membrane, suggesting the fixed positive charges in the inhibitory membrane.
The effects of soaking the skin in water at various temperatures on the subsequent ability to sweat
Authors: Brebner D. F. , Kerslake D. McK.
Published: December 2014

1. The ability of two human subjects to produce sweat was measured before and after immersion for up to 4 hr in water at 32‐36° C (soak).

2. The ability to produce sweat declined about 4 times as rapidly when the subject was soaked at 36° C as at 32° C.

3. The rate of decline characteristic of soaking at 36° C was shown by subjects exercising in water at 35° C, but not at rest at 35° C. The difference appeared to be related to the presence or absence of moderate sweating (300 g/hr) during the soak. At higher rates there was no further increase in the rate of decline.

4. Soaking at 39° C for 5 min, after which the water temperature was reduced to 33° C, caused a decline consistent with the supposition that while the subject was sweating the rate of decline was the same as that at 36° C and for the rest of the time the same as that at 32° C.

5. It is concluded that the rate of decline is increased if the sweat ducts are perfused, and some possible mechanisms are discussed.
The origin of acetylcholine released from guinea‐pig intestine and longitudinal muscle strips
Authors: Paton W. D. M. , Zar M. Aboo
Published: December 2014

1. Strips of longitudinal muscle can be obtained from guinea‐pig ileum either retaining or free from Auerbach's plexus.

2. The denervated strip is unresponsive to electrical stimulation by brief shocks, whether given singly or in trains; it also fails to respond to nicotine or dimethylphenylpiperazinium iodide (DMPP), and eserine causes no spasm.

3. Denervated strips neither contain detectable acetylcholine (< 0·4 ng/mg), nor release it spontaneously (< 5 pg/mg/min) or in response to stimulation (< 31 pg/mg/min). The acetylcholine metabolism of the innervated strip is therefore that of the adherent Auerbach's plexus. Innervated strips had a mean acetylcholine content of 28 ng/mg, a mean resting output of 94 pg/mg/min and an output in response to stimulation at 10 c/s of 700‐1200 pg/mg/min.

4. By comparing the responses of innervated and denervated strips it was concluded that arecoline, methylfurmethide, α,β‐ethylal‐γ‐tri‐methylammonium propanediol iodide (2268 F), muscarine, histamine, tremorine, oxytocin, and substance P, like acetylcholine, act primarily on the smooth muscle directly; and that angiotensin, barium, potassium, m‐bromophenyl choline ether and 5‐hydroxytryptamine have a progressively increasing proportionate effect on the nerve plexus. Nicotine and DMPP were inactive in the absence of the plexus.

5. The longitudinal muscle with its accompanying plexus contains about one quarter of the acetylcholine of the whole ileum, and is responsible for about one fifth of the output to electrical stimulation.

6. The volley output of acetylcholine by the innervated strip declines sharply as rate of stimulation increases. Output of acetylcholine was reduced by morphine and by cocaine, particularly when resting or when stimulated at low rates.

7. Acetylcholine output by whole ileum from guinea‐pig declines in the absence of glucose, but is insulin‐independent. Output by strips of ileum from rats made diabetic with alloxan was similar to that from normal rats.

8. The similarity in properties of acetylcholine output from innervated strips, where it must come from nervous tissue, to that from whole ileum, and the insulin‐independence of output from whole ileum suggest that the whole of the acetylcholine output of intestine is nervous in origin.

9. Comparison of the acetylcholine metabolism of the innervated strip with that of the superior cervical ganglion suggests that the typical features of the former (high resting output, high volley output at low rates, low minute output at high rates of stimulation, and sensitivity to morphine) may be linked with the absence of specialized neuro‐effector junctions and represent a relatively primitive transmission process.
The action of caffeine on the activation of the contractile mechanism in striated muscle fibres
Authors: Lüttgau H. C. , Oetliker H.
Published: December 2014

1. The effect of caffeine on the initiation of isometric tension in isolated twitch muscle fibres of the frog was recorded with a mechano‐electrical transducer.

2. In Ringer solution as well as in solutions containing 95 m
M‐K2SO4, caffeine (6‐10 m
M) caused reversible contractures. Tension of maximal potassium contractures was reached with a half‐time of 2‐4 sec.

3. Caffeine caused a shift to lower potassium concentrations of the S‐shaped curve which relates peak tension to log. [K]o or membrane potential. In subthreshold concentrations of caffeine (1·5 m
M) the potassium concentration at which half of maximal tension was reached shifted from 30 to 16 m
M‐K (‐39 to ‐53 mV).

4. In the ‘steady state’ the ability of fibres to develop tension is related to log. [K]o or membrane potential by an S‐shaped curve whose half value shifted from 28 to 45 m
M‐K (‐41 to ‐29 mV) when 1·5 m
M caffeine was applied.

5. Fibres were most sensitive to caffeine at membrane potentials between ‐50 and ‐20 mV.

6. The mechanical activity caused by caffeine was ‘stabilized’ by an increase in [Ca]o or [Mg]o resembling the stabilizing action of these ions on potassium contractures or on the sodium permeability of excitable membranes.

7. Tetracaine in low concentrations (0·04‐0·1 m
M) increased the threshold for mechanical activation and shortened the plateau of potassium contractures. Higher concentrations (1‐2 m
M) suppressed mechanical activity completely.

8. Tetracaine, 0·04 m
M, was sufficient to suppress tension caused by a 100 times stronger concentration of caffeine. With higher concentrations of caffeine the inhibitory action of tetracaine could be reversed.

9. Fibres which were immersed in subthreshold concentrations of caffeine either in Ringer solution or in a solution with 95 m
M‐K2SO4 developed a strong contracture after a sudden drop in temperature from 20 to 1‐3° C.

10. The fast activation of the whole cross‐section of the muscle fibre caused by caffeine and its dependence on membrane potential, tetracaine and external alkali earth ions favours the idea that the drug acts at some part of the sarcotubular system which is easily accessible for external ions and drugs and in close connextion with the surface membrane.
Reticulospinal inhibition of transmission in reflex pathways
Authors: Engberg I. , Lundberg A. , Ryall R. W.
Published: December 2014

1. The effect of electrical stimulation of the brain stem on reflex transmission has been investigated in decerebrate cats after partial transection of the spinal cord.

2. Brain stem stimuli that do not evoke inhibitory post‐synaptic potentials (IPSPs) in motoneurones or primary afferent depolarization may still effectively depress the excitatory and inhibitory synaptic actions evoked from the flexor reflex afferents (FRA) and from Ib afferents. There is no effect on post‐synaptic potentials from Ia afferents or on Renshaw IPSPs. The depression is not associated with any measurable change in conductance over the motoneuronal membrane.

3. There is also inhibition from the brain stem of transmission from the FRA (but not from Ia and Ib afferents) to primary afferent terminals and to ascending spinal pathways.

4. It is concluded that this inhibition from the brain stem is exerted at an interneuronal level in spinal reflex paths.

5. The inhibitory action is evoked from the region of Magoun's inhibitory centres in the brain stem and is mediated by axons with a conduction velocity of at least 20 m/sec. The axons are distributed in the dorsal part of the lateral funicle.

6. The pathway mediating the inhibition from the brain stem is named the dorsal reticulospinal system. Its possible role in maintaining the decerebrate control of reflexes is discussed and related to the problem of a selective control of some paths from a primary afferent system.
A relation between the chain length of fatty acids and the slowing of gastric emptying
Authors: Hunt J. N. , Knox M. T.
Published: December 2014

1. Test meals of solutions and suspensions of potassium and sodium salts of a series of saturated fatty acids, from C2 to C18, were given to healthy subjects.

2. From the volume of these meals recovered after a fixed interval the relative effectiveness of the salts of the acids in slowing gastric emptying was assessed.

3. On a molar basis the salts of fatty acids from acetic up to decanoic were relatively ineffective in slowing gastric emptying.

4. The salts of fatty acids with 12‐18 carbon atoms were much more effective than those with up to 10 carbon atoms. Myristate was the most effective of the salts.

5. Buffering the test meals with 33 m
M sodium citrate increased the effectiveness of the salts in slowing gastric emptying.
Thalamic projection of muscle nerve afferents in the cat
Authors: Mallart A.
Published: December 2014

1. Evoked responses on stimulation of hind‐ and forelimb muscle nerves have been recorded in the ventro‐postero‐lateral (VPL) and centre median (CM) nuclei of the thalamus of the cat.

2. The stimulation of hind‐limb muscle afferents with increasing strength usually did not evoke a thalamic response, either in the CM or in the VPL, until the threshold for Group III muscle afferents was reached.

3. Short latency potentials were evoked in the VPL on stimulation of low threshold Group I muscle afferents from forelimbs. The projection zone occupies the dorso‐medio‐rostral part of the nucleus.

4. An attempt was made to locate the medullary relay for forelimb Group I afferents either in the lateral part of the cuneate or in external cuneate.

5. Low threshold afferents from forelimb muscle nerves do not project to the CM. CM responses began to appear only when the threshold for Group II muscle nerve fibres was reached.

6. Group II afferents from hind‐ or forelimb muscle nerves projecting to the CM are probably not connected to spindle secondary endings.

7. The role played by muscle afferents in the somesthetic mechanisms is briefly discussed.
On the mechanism by which calcium and magnesium affect the spontaneous release of transmitter from mammalian motor nerve terminals
Authors: Hubbard J. I. , Jones S. F. , Landau E. M.
Published: December 2014

1. The frequency of miniature end‐plate potentials (m.e.p.p.s) was recorded from neuromuscular junctions in rat diaphragm phrenic nerve preparations in vitro after preparations had soaked in solutions containing Ca in concentrations between 10−10 and 10−2
M and a similar range of [Mg].

2. Ethylenediamine tetra‐acetate (EDTA) and ethyleneglycol bis (β‐aminoethyl ether) tetra‐acetate (EGTA) buffers were added to prepare solutions with [Ca] and [Mg] below 10−4
M. A computer program was used to estimate the free [Ca2+] in these solutions, and it was shown that the effects of Ca could be attributed to the free [Ca2+] in the bathing solution.

3. M.e.p.p.s could still be detected without difficulty after soaking preparations for 6‐8 hr in solutions containing EDTA or EGTA buffers and no added Ca. The basal frequency was unchanged upon exhibition of Ca in concentrations up to 10−5
M and/or Mg in concentrations up to 10−3
M.

4. Ca in concentrations of and above 10−4
M accelerated m.e.p.p. frequency from the basal level. This effect reached a maximum in [Ca] of 10 m
M and raising the [Ca] above this level did not further change frequency. These effects were explained by the combination of Ca molecules with a nerve terminal receptor site. It was postulated that this combination allosterically activated the spontaneous release mechanism.

5. Mg could accelerate m.e.p.p. frequency in the absence of added Ca. The interactions of Ca and Mg upon m.e.p.p. frequency indicated that Ca and Mg competed for the same sites.

6. Raising the [H+] of the bathing medium accelerated m.e.p.p. frequency. This effect was thought to be exerted partly by combination with the same receptor sites as Ca and Mg and partly by variation of the ionization of the CaCl2 of the bathing solution.
The influence of previous salt ingestion on the renal function of sheep subjected to intravenous hypertonic saline
Authors: Potter B. J.
Published: December 2014

1. Sheep, which had access to a solution containing 1·3% sodium chloride as their sole source of drinking water for 6 months or more, were infused with a hypertonic solution (10%) of sodium chloride, and their ability to tolerate this salt load was compared with that of a similar group of sheep which drank only rain water.

2. The sheep which drank the rain water were often affected by the infusion and exhibited signs resembling potassium deficit. No such signs were apparent in the animals which consumed saline water.

3. Glomerular filtration rates were increased in all sheep by the hypertonic saline infusion, the increases being greater in the sheep which were maintained on the saline water. Effective renal plasma flow rates, though extremely variable, behaved in a similar manner.

4. Plasma values for sodium and chloride were increased in all sheep, but remained at a higher level for a longer period in the sheep which consumed rain water. The diuresis produced by hypertonic saline appeared to persist for a longer period in the sheep which drank rain water, while the excretion of sodium and chloride tended to be greater in the sheep maintained on saline water.

5. Plasma potassium was reduced in all sheep and urinary excretion of potassium increased. The latter response was more pronounced in the sheep which drank the rain water.

6. Filtered loads of sodium, chloride and potassium were greater in the sheep which were accustomed to drinking saline water. However, the amounts of potassium excreted were greater than those filtered in the rain water sheep and less than those filtered in the sheep which drank saline water. It therefore seems that secretion of potassium into the kidney tubules predominated in the former group and reabsorption prevailed in the latter.

7. Reabsorption of free water in excess of solute was greater in the kidney tubules of the sheep which drank saline water.

8. Increased blood volume and greater dilution of plasma proteins occurred in the sheep which drank rain water.
The effect of temperature on the competitive inhibition of glucose transfer in human erythrocytes by phenolphthalein, phloretin and stilboestrol
Authors: Forsling Mary L. , Widdas W. F.
Published: December 2014

1. Phenolphthalein, like other diphenols, has been shown to be a competitive inhibitor of the facilitated transfer system for glucose in the human erythrocyte.

2. The concentration producing 50% inhibition is lower at low temperatures and increases steadily over the temperature range 10‐40° C. An Arrhenius plot of the results gives a slope of 19,300 cal/mole.

3. The effect of temperature on inhibition by phloretin and stilboestrol has also been studied. The temperature variation of the concentration of phloretin giving 50% inhibition is similar to that for phenolphthalein, but that for stilboestrol is much less.

4. There is a high cell/medium distribution ratio for stilboestrol, and the possibility that this may affect the temperature dependence of the aqueous concentrations required to give 50% inhibition is discussed.
Thyroxine feed‐back on the regulation of thyrotrophin secretion*
Authors: Panda J. N. , Turner C. W.
Published: December 2014

1. The role of thyroid hormone as a feed‐back at the hypothalamic level in the control of thyrotrophin (TSH) secretion and release has been investigated by estimating the plasma and pituitary TSH levels following intrahypophysial and intrahypothalamic thyroid autotransplants.

2. Thyroidectomized rats bearing thyroid autotransplants in the pituitary had a significantly lower (P < 0·001) plasma TSH than that of controls at 26° C but not at 4° C.

3. Thyroidectomized rats bearing thyroid autotransplants in the supraoptic area showed a significantly lower (P < 0·001) level of plasma TSH and higher pituitary TSH at 4° C but not at 26° C.

4. Study with both unilaterally and bilaterally thyroidectomized rats bearing thyroid autotransplants either in the pituitary or in the hypothalamus revealed that thyroxine feed‐back operates at pituitary level in normal situations (26° C) and there exists a feed‐back through higher centres, specifically the TSR secreting area of the hypothalamus, in situations demanding higher thyroid function, as in cold exposure.
The release of a bradykinin‐like pulmonary vasodilator substance in foetal and new‐born lambs
Authors: Campbell A. G. M. , Dawes G. S. , Fishman A. P. , Hyman A. I. , Perks A. M.
Published: December 2014

1. Exposure to glass of whole blood from anaesthetized foetal lambs (at 0·6‐0·95 of term) causes the rapid development of a potent pulmonary vasodilator agent.

2. The formation of the vasodilator agent on exposure to glass, its disappearance with time, and the inhibition of its production by soya bean trypsin inhibitor, suggest that it is bradykinin.

3. Small doses of bradykinin (∼ 1 ng/kg) cause pulmonary vasodilatation on close arterial injection. Neither this, nor the vasodilatation caused by glass‐exposed whole blood, are affected by agents which block the vasodilator actions of acetylcholine, isoprenaline or histamine.

4. Exposure of foetal plasma and/or red cells to glass rarely caused the development of a pulmonary vasodilator agent. Maternal plasma was always active. Injection of the buffy coat from foetal blood caused pulmonary vasodilatation.

5. The capacity of plasma from sheep at different ages to produce kinin(s) was examined by assay on the isolated rat's uterus. In the foetus activity was very low; it increased with age.

6. In adolescent lambs 5‐14 weeks after birth injection of ∼ 10 ng/kg bradykinin into the pulmonary artery caused only a trifling vasodilatation; this was greater when pulmonary vasoconstriction was induced by lung collapse, hypoxaemia and hypercapnia.

7. The possible physiological consequences of these findings are discussed.
An analysis of the reflex systemic vasodilator response elicited by lung inflation in the dog
Authors: Daly M. de Burgh , Robinson B. H.
Published: December 2014

1. A maintained inflation of the lungs caused a reflex reduction in total systemic vascular resistance in anaesthetized dogs under conditions in which the systemic circulation was perfused at constant blood flow and the arterial blood PO2 and PCO2 were maintained constant.

2. The fall in systemic arterial perfusion pressure evoked by inflation of the lungs was accompanied by an increase in blood flow to the lower limbs and a reduction in their calculated vascular resistance. Since the fall in resistance occurred when the limb was perfused either at constant pressure or at constant blood flow, it must be due to vasodilatation.

3. Lung inflation caused vasodilatation in skin, muscle, and in the splanchnic vascular bed. The responses in vertebral circulation were, however, small and variable.

4. The vasodilator responses in the vascular territories studied were reflex in nature, being abolished by cutting the cervical vagosympathetic nerves, in which run the afferent fibres, or by interrupting the sympathetic pathways to the blood vessels.

5. In the intact limb, muscle, skin and splanchnic vascular bed, the vasodilator responses to lung inflation were unaffected by atropine or propranolol, but were abolished by hexamethonium, dibenyline and bretylium tosylate, indicating that they were due predominantly to a reduction in the activity in sympathetic adrenergic vasoconstrictor fibres.
Thresholds of cortical activation of muscle spindles and α motoneurones of the baboon's hand
Authors: Koeze T. H. , Phillips C. G. , Sheridan J. D.
Published: December 2014

1. Much current thinking about voluntary movement assumes that the segmental γ loops can function as a servomechanism operated by the brain. However, the α motoneurones of the baboon's hand receive a powerful monosynaptic (CM) projection from the precentral gyrus. If servo‐driving from the same cortical area is to be possible, it must project independently to the fusimotor neurones and have sufficient power to increase the afferent signalling from the muscle spindles. The cortical thresholds for contraction of m. extensor digitorum communis and for acceleration of the discharges of its muscle spindles have therefore been compared.

2. Significant results in this context require that the spindles studied be coupled in parallel with the responding extrafusal muscle fibres. Many spindles were not unloaded by the submaximal contractions evoked by cortical stimulation, although all so tested were unloaded by maximal motor nerve twitches. Reasons are given for thinking that such apparent lack of parallel coupling is an artifact of complex intramuscular anatomy and limitation of shortening by ‘isometric’ myography.

3. A brief burst of corticospinal volleys at 500/sec, which is specially effective in exciting α motoneurones over the CM projection, failed to excite spindle afferents at or below the threshold for a cortical ‘twitch’.

4. In a few epileptiform discharges, bursts of spindle acceleration occurred independently of the clonic contractions. A relatively direct and independent cortico‐fusimotor (CF) projection may therefore exist.

5. Prolonged near‐threshold stimulation at 50‐100/sec, which allows time for temporal summation in the less direct projections (e.g. cortico‐interneuronal, cortico‐rubro‐spinal) and does not cause frequency‐potentiation at CM synapses, gives abundant evidence of independent α and fusimotor projections, whose actions hardly outlast the stimulation period.

6. Although independent CF projections would permit servo‐driving in natural movements of the hand (given adequate loop gain), there has been no evidence of servo‐driving by cortical stimulation or in the spontaneous contractions of light anaesthesia.

7. Independent projections would provide for controlled αγ co‐excitation in the servo‐governing of natural movements (Matthews, 1964).

8. Evidence is reviewed that the CM projection itself may be part of an important control loop for voluntary movement in primates. A corollary would be a diminished importance of CF projections for segmental loops and an increased importance for maintaining the spindle input to cortical loops.
Direct measurements of membrane potential and membrane resistance of human red cells
Authors: Lassen U. V. , Sten-Knudsen O.
Published: December 2014

1. In order to evaluate the membrane potentials calculated from the distribution of chloride ions in human red cells and plasma, it is desirable to have a direct measurement of the transmembrane potential of these cells.

2. A method has been devised for introducing a capillary micro‐electrode into human red cells. The method allows simultaneous measurements of potential and membrane resistance with only one micro‐electrode located in the cell.

3. Upon impalement of single cells in plasma, a scatter of membrane potentials and of resistance values was obtained. The potential drop never exceeded ‐14 mV and the maximum resistances were about 7 Ω. cm2. Positive potentials were obtained on impalement of red cell aggregates.

4. Arguments are given to support the view that it is in these cells which suffer least damage from the impalement that maximum values of membrane potentials and resistances are observed. The errors caused by the change in the liquid junction during the impalement have been estimated.

5. As judged from this study, it seems permissible under normal conditions to calculate the membrane potential of the red cell from the chloride concentrations in plasma and in intracellular water.
Activity of cells in the lateral vestibular nucleus as a function of head position
Authors: Fujita Y. , Rosenberg Jay , Segundo J. P.
Published: December 2014

1. The spike activity of cells in the lateral vestibular nucleus was recorded in cats anaesthetized with pentobarbital sodium. Natural labyrinthine stimulation was applied by fixing the animal at different positions reached through roations about a longitudinal or transverse axis.

2. The majority of cells responded to rotations only about the longitudinal axis. Two types of response were found. The first was characterized by a transient change in activity which occurred only during the movement. The second type had an initial transient component and a subsequent steady component that persisted as long as the head remained fixed.

3. The interspike interval means, standard deviations, histograms and autocorrelograms of the steady response components of cells sensitive to lateral tilt were calculated. In every cell the relation between the head position with respect to gravity and the mean interspike interval of the steady discharge showed two main features. (a) ‘Directional sensitivity’: the mean interval increased following rotation in one sense, and decreased following rotation in the other. In twenty‐two out of thirty‐three cells, the mean increased when the recording side was raised. The remaining cells showed the opposite relation. (b) ‘Multivaluedness’: each particular position is associated with several different values of mean interval and these values had a relatively wide scatter. The curve that resulted from joining points in the order in which they occurred during the experiment was either closed, open, or combined closed and open portions.

4. The standard deviations, histograms and autocorrelograms also showed directional sensitivity and multivaluedness with respect to position. Several types of interspike interval histograms and autocorrelograms characterized lateral vestibular activity. The forms of the histogram and the autocorrelogram of the discharge from each cell usually remained unchanged during stimulation.

5. The extensive spread of the multivaluedness implies that observation of the mean interspike interval of a specified cell can lead only to a probabilistic statement about head position. Joint observations of mean, standard deviation and histogram, or joint observation of several cells or knowledge of the previous history of the movement may lead to a more accurate determination of position.

6. Experiments in animals with only one labyrinth showed that each labyrinth can both accelerate and decelerate activity in both vestibular nuclei.
Frequencygrams of spindle primary endings elicited by stimulation of static and dynamic fusimotor fibres
Authors: Bessou P. , Laporte Y. , Pagès B.
Published: December 2014

1. Frequencygrams of cat spindle primary endings, obtained by the method described by Bessou, Laporte & Pagès (1968), were elicited by the stimulation of single static and dynamic fusimotor fibres.

2. Stimulation of static fibres by single stimuli may elicit: (i) no response, (ii) responses of small amplitude, (iii) responses of large amplitude with a pause after the rising phase.

3. Stimulation of static fibres by repetitive stimuli gives frequencygrams resembling records of tetanic contraction of skeletal muscle. At a frequency of stimulation of 180‐200/sec periodic oscillations are perceptible on the plateau of the frequencygram.

4. Stimulation of dynamic fibres by single stimuli may elicit: (i) no response, (ii) responses smaller and longer than the responses given by static fibres.

5. When the muscle is stretched the amplitude of the responses elicited by dynamic fibres decreases whereas the amplitude of the responses given by static fibres increases.

6. Frequencygrams obtained by repetitive stimulation of dynamic fibres show periodic oscillations only at low rates of stimulation. At rates of stimulation higher than the minimal rate giving frequencygrams with a smooth contour, the amplitude of the frequencygram increases.