bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Absorption of Glycine and Glycine Oligopeptides by the Rat
Authors: Peters T. J. , MacMahon M. T. 
Published: August 2015

1. Samples of portal venous and femoral arterial plasma and mesenteric lymph were collected from unanaesthetized rats before and during the intra-duodenal infusion of high concentrations (100 mmol/l) of glycine or glycine oligopeptides (up to and including tetraglycine).
2. There was a marked increase in the concentration of free glycine, and a small amount of diglycine was detected in all the fluids when the peptides were infused but not during the infusion of free glycine. No other glycine oligopeptides were detected.
3. Mesenteric lymph contained a similar concentration of glycine and diglycine to that found in portal blood, suggesting that the mesenteric lymph is a dialysate of portal plasma.
4. The results are interpreted as supporting a dual localization of peptidases within the enterocyte; glycine oligopeptides are hydrolysed to diglycine and free glycine at the brush border and the diglycine is hydrolysed within the cytoplasm.
Studies on the Sympathetic Control of Normal and Diseased Synovial Blood Vessels: The Effect of α and β Receptor Stimulation and Inhibition, Monitored by the 133Xenon Clearance Technique
Authors: Dick W. C. , Jubb R. , Buchanan W. W. , Williamson J. , Whaley K. , Porter B. B. 
Published: August 2015

1. The half-life (T½) of the disappearance curve of 133Xe from the knee joint has been used as an indirect measure of synovial perfusion.
2. The effects of intra-articularly administered isoprenaline and noradrenaline and their respective blocking agents, propranolol and phentolamine, on the T½ values have been investigated in normal subjects and in patients with osteoarthritis and rheumatoid arthritis.
3. In normal subjects isoprenaline increased the clearance rate and this effect was blocked by propranolol. Noradrenaline decreased the clearance rate and this effect was blocked by phentolamine.
4. The injection of phentolamine in normal subjects caused an increase in synovial perfusion, suggesting the presence of a basal α-constrictor tone.
5. In the patients with osteoarthritis and rheumatoid arthritis quantitative differences were found in the responses to isoprenaline and noradrenaline and their respective blocking agents.
6. There appeared to be a qualitative difference in the case of phentolamine; it is possible that vasoconstrictor tone may be lost in inflamed joints.
Mechanisms of Dipeptide Uptake by Rat Small Intestine in Vitro
Authors: Cheng B. , Navab F. , Lis M. T. , Miller T. N. , Matthews D. M. 
Published: August 2015

1. The uptake of l-methionine and glycine as free amino acids, and from their dipeptides by everted rings of rat small intestine in vitro has been investigated. The concentrations used covered a wide range, including values likely to be near those found in the lumen of the intestine.
2. Though no intact peptides were found in the mucosal cells, evidence was obtained which showed that hydrolysis of the peptides was cellular at all concentrations. Total hydrolysis of peptides by the intestine was very great in relation to amino acid uptake over very short incubation times, suggesting that much hydrolysis took place superficially.
3. Except at the lowest concentrations, the rates of uptake of amino acids from the peptides were more rapid than from the equivalent amino acid mixtures. Competition for uptake between glycine and methionine was avoided when they were presented in the form of l-methionylglycine.
4. Anoxia inhibited uptake of methionine from free l-methionine and from l-methionyl-l-methionine. It also inhibited hydrolysis of l-methionyl-l-methionine by intact intestine, but not by intestinal homogenates, suggesting that peptide uptake may be energy-dependent. The l-amino acid oxidase of snake venom, which destroys l-methionine but has no effect on glycine or on the peptides studied, inhibited methionine uptake from peptides when present at high concentrations, suggesting that a major site of hydrolysis is enzyme-accessible.
5. It is suggested that there may be two modes of uptake of amino acids from oligopeptides: (1) surface hydrolysis by mechanisms closely linked to the amino acid entry mechanisms, and (2) peptide entry into the mucosal cells by a special mechanism, followed by intracellular hydrolysis.
Serum Protein Changes after Injury
Authors: Clarke H. G. Minchin , Freeman T. , Pryse-Phillips W. 
Published: August 2015

1. By means of a quantitative immunoelectrophoretic technique, serum protein changes have been followed in seven patients before and during the week following inguinal herniorrhaphy, and in a single case of influenza.
2. The twenty proteins studied are grouped according to whether they rise (orosomucoid, α1-antitrypsin, Gc-globulin, caeruloplasmin, haptoglobin, β1A–C-globulin and proteins numbered 45, 99, 101 and X); fall (pre-albumin, α2HS-glycoprotein and protein No. 9); or show no significant change (α2-macroglobulin, haemopexin). α1-Lipoprotein fell in the case of influenza but did not change in the hernia patients; α1-easily-precipitable-glycoprotein increased in the hernia cases only.
3. The nature of the ‘acute phase reaction’ and the factors which elicit it are discussed.
Modifications to the Technique of Two-Dimensional Immunoelectrophoresis
Authors: Davies D. R. , Spurr E. D. , Versey J. B. 
Published: August 2015

1. An examination of the technique of two-dimensional electrophoresis as developed by Minchin Clarke & Freeman (1968) has resulted in improvements for its routine use.
2. These include the use of smaller plates, a re-designed modular electrophoresis tank and modifications in the method of preparing the plates and in the process of running the electrophoresis.
The Effect of Lung Deflation on Breathing in Man
Authors: Guz A. , Noble M. I. M. , Eisele J. H. , Trenchard Diana 
Published: August 2015

1. The effect of lung deflation was studied during treatment of patients for spontaneous pneumothorax: (a) in four patients acute lung deflation was produced by opening the chest drain to the atmosphere and the immediate effect on breathing was observed and (b) breath-holding time and the ventilatory response to CO2 were determined on admission to hospital and after recovery in a further four patients.
2. Allowing one lung to deflate suddenly produced an immediate increase in respiratory rate and electrical activity in inspiratory muscles.
3. Maximum breath-holding times were always decreased by pneumothorax.
4. In the presence of pneumothorax, the ventilatory response to rebreathing CO2 was increased at the break point, the respiratory rate was increased and the Pco2 at the breakpoint decreased in three out of four patients.
5. These results are consistent with the hypothesis that lung deflation has a reflex excitatory effect on breathing (Hering—Breuer deflation reflex). If this hypothesis is correct, it would appear that the threshold for the reflex is higher than for other mammalian species.
Measurement of Interstitial ‘Fluid’ Pressure by Means of a Cotton Wick in Man and Animals: An Analysis of the Origin of the Pressure
Authors: Snashall P. D. , Lucas J. , Guz A. , Floyer M. A. 
Published: August 2015

1. A method for measuring interstitial ‘fluid’ pressure by using a wick consisting of long-stranded cotton wool at the interface of the tissue is described.
2. A correct measurement of hydrostatic fluid pressure was obtained when the wick, connected to a suitable transducer, was applied to filter paper in which the channels contained fluid at a known subatmospheric pressure.
3. A mean subatmospheric pressure of −1.6 cmH2O was recorded in the subcutaneous tissue of the normally hydrated frog; pressure fell with dehydration and rose with overhydration.
4. A mean subatmospheric pressure of −2.8 cmH2O was recorded in the subcutaneous tissues of the abdominal wall and scalp of the normally hydrated rat. Simultaneous measurements made at symmetrical sites showed a high degree of correlation.
5. A comparison of interstitial ‘fluid’ pressure in the subcutaneous tissues of the scalp (measured by a wick) and the abdominal wall (measured by a Guyton capsule), in both anaesthetized and conscious rats showed some degree of correlation. There was, however, a wide scatter of values.
6. The interstitial ‘fluid’ pressure in the rat, measured by both wick and capsule, became more negative when the animals underwent frusemide diuresis; the capsule pressures fell more rapidly for a given degree of fluid loss.
7. The wick method was applied to the subcutaneous tissues of the arm in normal man; a mean atmospheric pressure of −3.4 cmH2O was recorded in five subjects. There were no untoward sequelae.
8. The forces responsible for the measured pressure have been analysed. The recorded subatmospheric interstitial ‘fluid’ pressure in the rat rose towards atmospheric pressure and sometimes became positive when the wick was removed, soaked in increasing concentrations of hyaluronic acid, and reinserted in the tissues. This did not happen in similar experiments in which the wick was soaked in bovine albumin, rat plasma or saline. The large macromolecules of hyaluronic acid therefore exert a force which opposes the forces responsible for the subatmospheric interstitial pressure.
9. It is suggested that the apparent subatmospheric hydrostatic pressure is due to the osmotic forces developed by the hyaluronic acid molecules in the interstitial tissues trapped by their mutual entanglement in a sieve of collagen fibrils acting as a semipermeable membrane.
Potassium and Sodium Distribution in Cardiac Failure
Authors: Cox J. R. , Horrocks P. , Speight Carol J. , Pearson Rosemary E. , Hobson Norma 
Published: August 2015

1. Total body water, extracellular fluid, total exchangeable potassium and total exchangeable sodium were measured by the multiple isotope-dilution technique in eight patients with congestive cardiac failure. Measurements were made on each patient while in failure and then again after treatment and recovery.
2. Compared with five control subjects in whom the same measurements were made, patients in failure had an excess of total body water, extracellular fluid and total exchangeable sodium, and had less total exchangeable potassium.
3. There was a decrease in total exchangeable sodium and an increase in total exchangeable potassium on recovery from congestive cardiac failure
4. After treatment of cardiac failure, intracellular potassium increased and intracellular sodium was decreased.
5. The low total exchangeable potassium in cardiac failure is not simply due to loss of lean body mass.
The Intramedullary Connections of the Area Postrema Involved in the Central Cardiovascular Response to Angiotensin II
Authors: Joy M. D. 
Published: August 2015

1. The intramedullary connections of the area postrema involved in the central cardiovascular response to angiotensin were studied in the chloralose-anaesthetized greyhound.
2. In the intact animal the response to vertebral arterial infusions of angiotensin (32 ng/min for 5 min) was decreased by unilateral ablation of the area postrema suggesting that both areas postrema contribute to this response.
3. In the animal in which both vagi were blocked by cooling, the residual sympathetically mediated pressor response was unmodified by unilateral ablation of the area postrema suggesting that each area postrema can mediate the central sympathetic component of the response to angiotensin.
4. In the animal in which one vagus only had been blocked, unilateral ablation of the area postrema, irrespective of side, did not abolish the central cardiovascular response to angiotensin demonstrating that each area postrema can influence both vagi.
5. Midcollicular transection of the midbrain did not significantly alter the response to vertebral arterial infusions of angiotensin. This demonstrated that the central cardiovascular response to angiotensin is not dependent on connections with centres above the midbrain.
6. These results are consistent with the concept that the angiotensin-area postrema system is a neuro-humoral vasomotor centre afferent pathway.
Ventilatory Function in Healthy Adult Nigerians
Authors: Femi-Pearse D. , Elebute E. A. 
Published: August 2015

1. Static and dynamic lung volumes (VC, FEV1, FRC, ERV, RV and TLC) have been determined in 291 adult healthy Nigerians (174 males and 117 females).
2. Prediction formulae of various authors on Caucasians and South African Bantu have been applied to the Nigerian data. The results show significantly smaller VC, FEV1, FRC, RV, TLC and RV/TLC in Nigerians than in Caucasians. The VC, FEV1 and FRC of Nigerians were similar to those of South African Bantu.
3. ERV values were similar to those previously reported by other authors for Caucasians. The combination of lower RV values and similar ERV indicates the possibility of less ‘basal airway closure’ in Nigerians.
The Effects of Hypoxia on Myocardial Blood Flow and Oxygen Consumption: Negative Role of Beta Adrenoreceptors
Authors: Vance J. P. , Parratt J. R. , Ledingham I. McA. 
Published: August 2015

1. Myocardial blood flow was measured by using a 133xenon clearance technique in closed-chest dogs anaesthetized with trichlorethylene. A gradual decrease in the inspired oxygen tension resulted in an increase in myocardial blood flow only when the Pa,o2 fell to between 30 and 35 mmHg.
2. When hypoxia was rapidly induced and sustained for a mean period of 18.3 min, myocardial blood flow markedly increased (from a mean of 118 ± 5 to 162±6 ml 100 g−1 min−1). There was a critical mean arterial oxygen tension (35 mmHg) above which increases in myocardial blood flow did not occur. This corresponded to a mean coronary sinus Po2 of 18 mmHg or an oxygen content of 50 ml/100 ml. These flow increases were not dependent on changes in arterial or coronary sinus pH or carbon dioxide tension, nor were they dependent on changes in perfusion pressure or heart rate.
3. Despite the fact that oxygen availability was substantially decreased, myocardial oxygen consumption was maintained throughout the period of hypoxia by means of increased oxygen extraction.
4. Towards the end of the hypoxic period, Pa,co2 rose significantly from 40 ± 1 to 48 ± 1.5 mmHg. There was no significant change in the non-respiratory component of acid-base balance.
5. During prolonged hypoxia (more than 30 min) myocardial blood flow remained consistently elevated, but oxygen consumption tended to fall progressively and this was associated with an increasingly severe metabolic acidosis. The haemodynamic and oxygen consumption changes returned to normal within a short time (15 min) after the resumption of a normal inspired oxygen concentration, as did the frequently observed electrocardiographic disturbances.
6. The responses to hypoxia were unaffected by a combination of atropine and propranolol. There was no evidence either that hypoxia-induced coronary vasodilatation was mediated through vascular β-adrenoreceptors or that propranolol interfered with the self-regulating control of myocardial blood flow.
It has been recognized for some time that hypoxia is capable of producing considerable increases in blood flow in the myocardium (Hilton & Eichholtz, 1925; Eckenhoff, Haf kenschiel, Landmesser & Harmel, 1947; Berne, Blackmon & Gardner, 1957; Feinberg, Gerola & Katz, 1958; Aukland, Kiil, Kjekshus & Semb, 1967). Little is known, however, about the exact relationship between arterial oxygen tension and myocardial blood flow. Further, although several factors associated with hypoxia are known to influence myocardial blood flow, the relative importance of each is uncertain; such factors include a direct effect of hypoxia on coronary vascular smooth muscle and indirect effects relating to changes in perfusion pressure, heart rate, extravascular support and associated metabolic disturbances. Likewise, the influence of neurogenic factors on myocardial vascular tone during hypoxia has not been systematically examined.
The Role of the Diaphragm in the Sensation of Holding the Breath
Authors: Noble M. I. M. , Eisele J. H. , Frankel H. L. , Else Wendy , Guz A. 
Published: August 2015

1. Block of the phrenic nerves in three normal subjects, produced by injection of lignocaine in the neck, caused alleviation of the thoracic sensation during breath holding and prolonged breath-holding time.
2. Injection of lignocaine in the neck without nerve block had no effect on breath holding sensation or breath-holding time.
3. A patient with a spinal-cord transection at the third cervical segment with paralysed diaphragm and chest wall, had no sensation in the chest or abdomen during breath holding.
4. This patient maintained normal ventilation by using hypertrophied sternomastoid muscles. During breath holding he experienced no sensation in the neck despite the presence of sternomastoid contraction.
5. There is previous evidence that complete muscular paralysis abolishes breath-holding sensation but that paralysis of all muscles innervated from spinal segments below the eighth cervical has no effect.
The Validity of Measurement of Mean Whole Body Intracellular Hydrogen Ion Activity Using 5,5-Dimethyl-2,4-Oxazolidinedione
Authors: Makoff D. L. , Reid M. J. , Khayim Y. Bar , Kuyt F. 
Published: August 2015

1. To study the validity of mean whole-body intracellular hydrogen ion activity measurements ([H+]i) by the distribution of 14C-labelled 5,5-dimethyl-2,4-oxazo-lidinedione ([14C]DMO), eight anaesthetized dogs received three separate injections of iso-osmotic buffered chemical DMO, in cumulative doses of 50–2000 mg/kg body weight, following a control [H+]i determination by the 14C-tracer technique.
2. A correlation between dose of chemical DMO and measured [H+]i was found with a regression line of −Δ[H+]i = 23.27 + 16.45 [log DMO dose −2.41].
3. Although the results are consistent with active transport of DMO across cell membranes, other possible explanations such as altered cell buffering capacity by DMO loading and variable sequestration of DMO in the gastrointestinal tract must be considered.
4. There is no evidence for cellular binding of DMO.
The Plasma Clearance and Liver Uptake of Iron from Transferrin of Low and High Iron Saturation
Authors: Fletcher J. 
Published: August 2015

1. Serum labelled with radioactive iron was adjusted to different degrees of iron saturation and clearance of the tracer from the circulation of rats and its uptake by liver and intestine were followed.
2. The results showed that: (a) plasma iron clearance did not vary according to whether labelled iron was attached to transferrin at high or low iron saturation; (b) uptake of labelled iron by the liver was greater from transferrin at high iron saturation than from transferrin at low saturation.
3. The results suggest the presence of a receptor mechanism in the liver similar to that previously shown in reticulocytes.
The Effect of Starvation and Diabetes on Glycolytic Enzymes in Human Adipose Tissue
Authors: Galton D. J. , Wilson J. P. D. 
Published: August 2015

1. The activities of hexokinase (EC 2.7.1.1) and phosphofructokinase (EC 2.7.1.11) have been studied in homogenates of adipose tissue taken from human diabetics, fasting and control patients.
2. Three isoenzymes of hexokinase were observed with apparent Km values for glucose of 1.04 × 10-5 m, 2.6 × 10-4 m and 2.9 × 10-4 m, respectively.
3. No change in activity of hexokinase was found in adipose tissue of untreated diabetics (n = 22), treated diabetics (n = 13) or non-diabetic controls. However, fasting was associated with a decrease of approx. 40% in the activity of hexokinase in adipose tissue.
4. In contrast, there was a marked decrease in the activity of phosphofructokinase in adipose tissue from untreated diabetics (n = 24) which was restored to normal by either insulin therapy or treatment by hypoglycaemic drugs.
5. There was a negative correlation between the phosphofructokinase/hexokinase ratio in adipose tissue and the fasting blood glucose (P = 0.01) and the 2 h blood glucose (P = 0.03) after an oral glucose load (50 g).
6. The functional significance of the changes in enzyme activities is discussed in relation to the glucose intolerance of diabetes.
Breathing Patterns and Regional Ventilation Distribution in Tetraplegic Patients and in Normal Subjects
Authors: Bake B. , Fugl-Meyer A. R. , Grimby G. 
Published: August 2015

1. The regional distribution of ventilation was studied with 133Xe techniques in the sitting position in six patients with complete traumatic transection of the cervical spinal cord, 3–40 months after the lesion, and in four normal subjects. The relative contributions of the rib cage and abdomen to ventilation were determined from chest-wall motions.
2. Total lung capacity (TLC) was decreased and residual volume increased in the patients. After correction for the decreased TLC, the distribution of the regional functional residual capacity in the tetraplegic patients was similar to that of the normal subjects. In the patients, where the abdomen contributed to about half of the tidal volume, decreased ventilation of basal regions was demonstrated from measurements of regional tidal volumes (Vtr) and regional 133Xe wash-in curves.
3. The distribution of ventilation in normal persons, however, was not changed by varying the relative contributions of the rib cage and abdomen to the tidal volume, as shown from Vtr and regional 133Xe wash-out measurements.
4. The results in the tetraplegic patients are interpreted as evidence of ‘small airway disease’, presumably from infection of the air way and impairment of the cough.
The Influence of Disodium Ethane-1-Hydroxy-1,1-Diphosphonate (Ehdp) on the Development of Experimentally Induced Urinary Stones in Rats
Authors: Fraser D. , Russell R. G. G. , Pohler Ortrun , Robertson W. G. , Fleisch H. 
Published: August 2015

1. Bladder stones composed of calcium hydrogen phosphate dihydrate, calcium oxalate mono- and di-hydrate and magnesium ammonium phosphate hexahydrate (struvite) were successfully induced in rats by various dietary manipulations and by implanting zinc pellets in the bladder.
2. The effect of a diphosphonate, disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP), given in the drinking water at concentrations of 0·0025, 0·05 and 0·5% (w/v), on the size and composition of these stones was examined.
3. All the concentrations of EHDP decreased the weight of the calcium oxalate calculi. In contrast, only the highest concentration of EHDP inhibited calcium hydrogen phosphate stone formation and the magnesium ammonium phosphate stones were unaffected.
4. The difference between the effects on calcium oxalate and magnesium ammonium phosphate stones is consistent with the finding that EHDP inhibited the precipitation of calcium oxalate from solution in vitro but had only a slight effect on magnesium ammonium phosphate precipitation.
5. It is suggested that EHDP might be of use in the prevention of some types of urinary stones in man.
Calcium Shift into Bone: A Calcitonin-Resistant Primary Action of Parathyroid Hormone, Studied in Rats
Authors: Robinson C. J. , Rafferty B. , Parsonsy J. A. 
Published: August 2015

1. Parathyroid hormone (PTH) injected intravenously into rats caused a small rapid uptake of simultaneously administered radioactive calcium into the skeleton.
2. This skeletal uptake of calcium occurs in many other species, including the monkey and probably man. It appears to be an initiating event in PTH action on bone.
3. Although calcitonin prevents PTH-induced bone resorption, it did not affect this early calcium shift.
4. This evidence is discussed in connection with the possibility of combining calcitonin with some other agent for the treatment of osteoporosis.