bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of Gluconeogenesis and Ketogenesis during Rest and Exercise in Diabetic Subjects and Normal Men
Authors: Sestoft L. , Trap-Jensen J. , Lyngsøe J. , Clausen J. P. , Holst J. J. , Nielsen S. L. , Rehfeld J. F. , De Muckadell O. Schaffalitzky 
Published: August 2015

1. The splanchnic—hepatic metabolism of glucose, lactate, pyruvate, alanine, glycerol, non-esterified fatty acids (NEFA), ketone bodies and oxygen were investigated in five normal men and six juvenile diabetic subjects at rest and during exercise after an overnight fast.
2. A linear relationship was found between load (arterial concentration multiplied by hepatic blood flow) and splanchnic—hepatic uptake of lactate, pyruvate, glycerol and NEFA. The uptake of alanine was highly sensitive to load, but was also regulated by the concentration of hepatic venous glucagon. The uptake of pyruvate was high in exercising diabetic subjects, who had a high lactate/pyruvate concentration ratio in hepatic venous blood.
3. The rate of uptake of the total measured gluconeogenic precursors was significantly higher in the diabetic group at a given load.
4. The rate of ketogenesis was linearly related to the NEFA load in both groups; however, the rate of ketogenesis was twofold at a given load in the diabetic group. The highest rates of ketogenesis were found coincident with the highest concentrations of glucagon in hepatic venous blood.
5. The observed antiketogenic effect of exercise was due to a decreased load of NEFA, mainly caused by a decrease in the hepatic blood flow.
The Carriers of Native Vitamin B12 in Normal Human Serum
Authors: Hall C. A. 
Published: August 2015

1. After fractionation of the vitamin B12-binding proteins of ten normal sera the components containing transcobalamin II and R-type binders of vitamin B12 respectively were studied for endogenous vitamin B12 content by two distinct systems of vitamin B12 assay.
2. The measurements of total serum vitamin B12 by either bioassay with Euglena gracilis or a radioisotope dilution assay agreed closely.
3. The native vitamin B12 carried by transcobalamin II was higher as measured by bioassay than by isotope dilution assay.
4. The presence of the transcobalamin II fraction of human serum altered the key reaction between the binding reagent of the isotope dilution assay, so that this assay failed to measure vitamin B12 quantitatively.
5. Probably, the mean fraction of plasma vitamin B12 carried by transcobalamin II is in the range 20–30%.
Effect of Isometric Hand-Grip Exercise on the Carotid Sinus Baroreceptor Reflex in Man
Authors: Mancia G. , Iannos J. , Jamieson G. G. , Lawrence R. H. , Sharman P. R. , Ludbrook J. 
Published: August 2015

1. The changes in R—R heart interval that result from step-increase and step-decrease in carotid sinus transmural pressure induced by a variable-pressure neck chamber were measured in seven normal men. Observations were made at rest, and during isometric hand-grip exercise at 24%, 44% and 64% of maximal voluntary contraction.
2. The response of heart interval to increase in carotid sinus transmural pressure was progressively and markedly diminished according to the strength of hand-grip. This effect was fully developed from the moment of onset of the exertion.
3. The response of heart interval to decrease in carotid sinus transmural pressure was much less consistently affected by hand-grip exercise.
Skeletal Blood Flow in Paget's Disease of Bone and its Response to Calcitonin Therapy
Authors: Wootton R. , Reeve J. , Spellacy E. , Tellez-Yudilevich M. 
Published: August 2015

1. Blood flow to the skeleton was measured by the 18F clearance method of Wootton, Reeve & Veall (1976) in 24 patients with untreated Paget's disease. In every patient but one, resting skeletal blood flow was increased. There was a significant positive correlation between skeletal blood flow and serum alkaline phosphatase and between skeletal blood flow and urinary total hydroxyproline excretion.
2. Fourteen patients were re-studied after they had received short-term (7 days or less) or long-term (7 weeks or more) calcitonin. Skeletal blood flow, alkaline phosphatase and urinary hydroxyproline excretion fell towards normal in every case. There was some evidence from the short-term studies that calcitonin produced a more rapid fall in skeletal blood flow than in alkaline phosphatase.
3. Glomerular filtration rate appeared to increase transiently in response to calcitonin.
Hepatic Metabolism of Aminopyrine in Patients with Chronic Renal Failure
Authors: Scherrer S. , Haldimann B. , Küpfer A. , Reubi F. , Bircher J. 
Published: August 2015

1. To evaluate potential alterations in hepatic metabolism of drugs occurring in patients with renal insufficiency the fate of aminopyrine was studied in 17 patients with chronic renal failure and in 27 normal subjects.
2. Although patients with chronic renal failure exhibited large variations, their aminopyrine plasma disappearance times (mean 0·62 ± sd 0·24 h−1) were significantly higher than those found in normal subjects (0·30 ± 0·07 h−1, P < 0·002).
3. 14CO2 derived from [dimethylamine-14C]aminopyrine disappeared from breath more rapidly in patients with chronic renal failure and a history of analgesic abuse (0·40 ± 0·04 h−1) than in control subjects (0·22 ± 0·03 h−1, P < 0·01) and in other patients with chronic renal failure (0·24 ± 0·04 h−1).
4. Dialysis treatment and serum creatinine concentrations were not correlated with the rates of aminopyrine metabolism. Two additional patients, however, with combined renal and hepatic disease, exhibited markedly slowed rates of aminopyrine demethylation.
5. Although chronic renal failure by itself might not alter microsomal drug metabolism it is concluded that, in patients with a history of abuse of phenacetin-containing analgesics, marked acceleration in aminopyrine N-demethylation may be observed.
Influence of Indomethacin on the Systemic and Pulmonary Vascular Resistance in Man
Authors: Wennmalm Å. 
Published: August 2015

1. Indomethacin, an inhibitor of the cyclo-oxygenase system that converts arachidonic acid into prostaglandins and related substances, was infused intravenously in 12 healthy volunteer subjects.
2. Systemic systolic and diastolic blood pressures and heart rate were recorded in all subjects, and in most of them also the systemic arteriovenous oxygen difference, the total oxygen uptake and the pulmonary arterial and wedge pressures.
3. The infusion of indomethacin was followed by a decreased cardiac output (from 7·3 ± 0·3 to 6·3 ± 0·3 litres/min) and an increased mean systemic blood pressure (from 92 ± 1 to 102 ± 1 mmHg), indicating an elevation of the total systemic vascular resistance (from 98 ± 4 to 124 ± 5 kPa)l−1 s) by indomethacin. The ventilation and the pulmonary vascular resistance did not change after the infusion of indomethacin.
4. The results suggest that products formed by the cyclo-oxygenase system at rest exert a relaxing effect in certain parts of the systemic vascular bed, thereby lowering the systemic vascular resistance.
Concurrent Estimation of Total Body and Exchangeable Body Sodium in Hypertension
Authors: Boddy K. , Brown J. J. , Davies D. L. , Elliott A. , Harvey I. , Haywood J. K. , Holloway I. , Lever A. F. , Robertson J. I. S. , Williams E. D. 
Published: August 2015

1. Total-body neutron-activation analysis in vivo was carried out in 11 hypertensive subjects to measure simultaneously the total body content of sodium, chlorine, calcium, phosphorus and nitrogen.
2. There was a highly significant correlation between total body sodium measured by activation analysis and total exchangeable sodium measured by a standard isotope-dilution technique (r = 0·92, P < 0·001). Exchangeable sodium averaged 80·3% of total body sodium.
3. The measured values of chlorine, calcium, phosphorus and nitrogen were similar to those for healthy subjects reported by others.
4. Activation analysis in vivo appears promising as an additional tool for investigating sodium metabolism in hypertension, as it is the only method available for determining the total body content of this element. The radiation dose (1 rem) is sufficiently low to permit repeated measurements in the same subject.
Subcellular Distribution of Hydrolase Activities for Glycine and Leucine Homopeptides in Human Jejunum
Authors: Nicholson J. A. , Peters T. J. 
Published: August 2015

1. The subcellular distribution of peptidase activities in the normal human jejunum against glycine and leucine homopeptides has been investigated with an analytical fractionation technique.
2. An 8000 g-min supernatant was prepared from homogenates of Crosby capsule biopsy specimens and subjected to isopycnic centrifugation in a Beaufay automatic zonal rotor.
3. The distribution of subcellular organelles in the gradient was established by measurement of organelle-specific marker enzymes.
4. A sensitive fluorimetric assay for glycine peptidase was developed and used for the localization of peptidase activity with peptides composed of from two to five glycine residues as substrates.
5. Glycine peptidase activity was located in the cytosol and in the brush-border membrane but the distribution of activity varied markedly with the chain-length of substrate; the longer the peptide the greater the proportion of activity associated with the brush border. Leucine peptidase showed a similar variation in cytosol—brush border distributions.
6. The results are consistent with concepts that suggest absorption and intracellular hydrolysis of small peptides and brush-border digestion of larger peptides.
Effects of Ileal and Caecal Resection on the Colon of the Rat
Authors: Scarpello J. H. B. , Cary B. A. , Sladen G. E. 
Published: August 2015

1. Rats were subjected to resection of either the distal 50 cm of small bowel, the caecum or a combined ileocaecal operation. The effects on stool production and growth were observed over the following 8 weeks. Subsequently measurements were made at various levels in the remaining gut of intestinal weight, mucosal thickness, mucosal adenosine 3′:5′-phosphate (cyclic AMP) concentration and the water and bile acid content of luminal material.
2. Rapid adaptation, in terms of growth and the production of formed stools, was seen after ile-ectomy or caecectomy. This was slower and less complete after ileocaecectomy. Changes in water content indicated that colonic absorption of water was normal after ile-ectomy but impaired after ileocaecectomy.
3. After ile-ectomy there was growth of the caecum but not colon, whereas after ileocaecectomy there was growth of the remaining colon.
4. The intraluminal bile acid concentration in the small-gut remnant was markedly decreased at 2 weeks with little further change at 8 weeks after ileal resection. The colonic intraluminal bile acid concentration was only modestly increased after ile-ectomy or ileocaecectomy.
5. When studied by a perfusion technique in vivo, deoxycholate (2·5 mmol/l) in intact rats induced a net secretion of water into the colon; by contrast the colon of 8 week ile-ectomized rats absorbed water, although this was at a reduced rate compared with control rats. Deoxycholate increased mucosal cyclic AMP concentrations in the intact rats but not in the ile-ectomized rats.
6. Sodium ricinoleate (5·0 mmol/l) inhibited colonic water absorption and when mixed with deoxycholate (2·5 mmol/l) the effect on water transport was summatory. However, ricinoleate either alone or with deoxycholate did not alter mucosal cyclic AMP concentrations.
7. These results demonstrate that the colon can absorb water effectively after ile-ectomy in spite of being exposed to increased concentrations of luminal bile acids. This may result in part from an altered mucosal response to secretagogues. If so this represents a form of functional adaptation by the colon to ileal resection.
Tidal Pressure/Volume and Flow/Volume Respiratory Loop Patterns in Human Neonates
Authors: Milner A. D. , Saunders R. A. , Hopkin I. E. 
Published: August 2015

1. Tidal pressure/volume and flow/volume respiratory loops were constructed from records obtained during 98 studies on 48 neonates of various ages and gestations. Records were obtained with a total body plethysmograph and an oesophageal balloon. Total pulmonary resistance was computed at five separate levels in the breathing cycle and results were expressed graphically as tidal resistance profiles by plotting total pulmonary resistance against percentage tidal volume above functional residual capacity.
2. Values obtained for standard pulmonary mechanical measurements and thoracic gas volume were similar to those of other workers. In addition six distinctive resistance profile patterns were found and related to different breathing patterns.
3. The technique appeared to be particularly useful in identifying air trapping and also demonstrated that total pulmonary resistance is open to misinterpretation when measured only at the mid-tidal-volume level, as is the present convention.
The Mechanism of Renomedullary Antihypertensive Action: Haemodynamic Studies in Hydronephrotic Rats with One-Kidney Renal-Clip Hypertension
Authors: Sušić D. , Sparks J. C. , MacHado E. A. , Kentera D. 
Published: August 2015

1. The protective action of the renal medulla was studied in one-kidney renal-clip hypertension in rats with unilateral hereditary hydronephrosis and almost complete atrophy of the medulla of the affected kidney.
2. Rats were unilaterally nephrectomized. The first group had a normal kidney remaining, and the animals from the second and third groups were left with a hydronephrotic kidney and received renomedullary and renocortical autotransplants respectively. Two weeks later all rats were made hypertensive by placing a silver clip (0·2 mm) on the renal artery.
3. From the fourth day after clipping until the end of the experiment blood pressure was found to be significantly (P < 0·01) lower in rats with medullary transplants than in the other groups. No differences in renal excretory function, plasma volume and plasma renin activity were found between the groups either before or during development of hypertension (5 and 21 days after clipping). Early in the course of hypertension (5 days) cardiac output was significantly (P < 0·05) lower in the rats with medullary transplants than in the other groups, although an increase in plasma volume was noted in all three groups. At that time no difference in total peripheral resistance was found between the groups.
4. The results are consistent with the hypothesis that the renomedullary antihypertensive substance(s) mitigates hypertension by preventing a hypertensive haemodynamic response to sodium/volume overload.
Excretion of Conjugated Bilirubin in the Isolated Perfused Rat Kidney
Authors: Gollan J. L. , Dallinger K. J. C. , Billing Barbara H. 
Published: August 2015

1. Renal mechanisms of conjugated bilirubin excretion have been studied in isolated rat kidneys perfused with a protein-free dextran medium, containing conjugated bilirubin isolated from human bile.
2. In nine perfused kidneys with a low glomerular filtration rate (GFR) (<0·5 ml/min) and depressed tubular function, there was a significant linear correlation between conjugated bilirubin clearance and GFR (r = 0·97).
3. In contrast, nine kidneys with a normal GFR (> 0·8 ml/min) and good tubular function exhibited substantial tubular reabsorption of filtered conjugated bilirubin (mean 74%). Reabsorption was proportional to the filtered conjugated bilirubin load and a tubular transport maximum was not observed even at high concentrations (144 μmol/l).
4. The fractional reabsorption of bilirubin was unchanged by the addition of sodium aminohippurate to the medium. Perfusion with an albumin medium (10 g/l) resulted in a tenfold reduction in conjugated bilirubin clearance.
5. These observations indicate that non-protein-bound conjugated bilirubin is freely filtered by the glomeruli and then largely reabsorbed in the tubules. Evidence of tubular secretion was not obtained.
6. Chromatographic separation of bilirubin conjugates showed that the proportion of di- to monoconjugates in the urine was greater than in the perfusate. Whether this indicated further conjugation by the kidney of the monoconjugates or differential clearance of the conjugates was not established.
Thyroid Function and Blood Pressure in Two New Strains of Spontaneously Hypertensive and Normotensive Rats
Authors: Vincent M. , Bornet H. , Berthezene F. , Dupont J. , Sassard J. 
Published: August 2015

1. The influence of thyroid function on the development of hypertension was studied in strains of spontaneously hypertensive (SH) and normotensive rats.
2. Surgical thyroidectomy decreased systolic blood pressure more markedly in SH rats than in normotensive rats. The effects of oral administration of 5 and 100 μg of thyroxine 24 h—1 100 g—1 were studied in the thyroidectomized animals. In the two strains the blood pressure returned to control levels only after administration of the larger dose.
3. The evolution of body weight, total plasma tri-iodothyronine (T3) and tetraiodothyronine (T4) concentrations were followed as a function of age in SH rats and normotensive rats from 5 to 21 weeks. At each age, SH rats showed significantly larger body weight and decreased T4 concentrations. Plasma T3 in SH rats was lower than in normotensive rats until 15 weeks of age, after which the difference was not significant. At 11 weeks, plasma free T3 and T4 concentrations were slightly lower in SH rats than in normotensive rats.
4. The more marked hypotensive effects of surgical thyroidectomy in SH rats cannot be related to increased thyroid function.
Effect of Hyperosmolar Stimuli and Coeliac Disease on the Permeability of the Human Gastrointestinal Tract
Authors: Wheeler P. G. , Menzies I. S. , Creamer B. 
Published: August 2015

1. Oral loads have been used to assess the permeability of the human gastrointestinal tract, with lactulose (mol. wt. 342), raffinose (mol. wt. 504), stachyose (mol. wt. 666) and a fluoresceinlabelled dextran (mol. wt. 3000) as marker substances. Timed urinary recovery of these substances, which are not metabolized, was measured by quantitative paper chromatography and direct fluorimetry, and the results were used as an indication of passive intestinal permeability.
2. Results in healthy adults showed that permeability to these markers was dependent on molecular size, even after correction for aqueous diffusion differences, such that a profile of restricted permeability could be described for this range of markers. Interpretation in terms of conventional pore theory suggested the presence of more than one population of pores.
3. Ingestion of solutions made hyperosmotic by inclusion of glycerol resulted in a large increase in permeability, in a pattern that suggested an increase in either the size or frequency of a range of smaller pores.
4. A similar increase in permeability and alteration in the profile of restriction was found in patients with coeliac disease.
5. The possible location of such pores in the gastrointestinal mucosa is discussed in relation to the cell membrane, the intercellular junction, and the sites of cell exfoliation.
Saline-Induced Natriuresis in the Dog without Prior Exposure of the Kidney to the Physical Effects of Expansion of the Extracellular Fluid Compartment
Authors: Klemmer P. J. , De Los Santos C. , Blythe W. B. 
Published: August 2015

1. Experiments were carried out in dogs in which renal perfusion pressure was reduced 40 min before beginning expansion of the extracellular fluid space by 10% with isotonic sodium chloride solution. Sodium excretion increased up to 590% of control values in spite of the fact that the filtered load of sodium was below that of the control period and circulating mineralocorticoids were not suppressed.
2. The findings indicate that, in the dog, prior exposure of the kidney to the volume-expanded state is not a prerequisite for natriuresis to occur.
Control of Enzymatically Inactive Renin in man under Various Pathological Conditions: Implications for the Interpretation of Renin Measurements in Peripheral and Renal Venous Plasma
Authors: Derkx F. H. M. , Wenting G. J. , Veld A. J. Man In 'T , Verhoeven R. P. , Schalekamp M. A. D. H. 
Published: August 2015

1. Human plasma contains two types of renin: one is active in its native form (active renin), the other has renin-like activity after exposure to low pH (inactive renin). Reactions of acid-activated plasma renin and kidney renin with either homologous or heterologous substrate showed identical Km values.
2. Peripheral venous values for active and inactive renin in essential hypertension (n = 22), renovascular hypertension (n = 14), primary aldosteronism (n = 12), adrenal insufficiency (n = 6) and control subjects (n = 13) were directly correlated. But the percentage of renin that was active varied widely.
3. After bilateral nephrectomy in 12 patients both active and inactive plasma renin fell, but did not completely disappear. Estimates of half-life in two patients were 30–80 min for active renin and 150–165 min for inactive renin.
4. Renal vein to peripheral vein ratios of active and inactive renin in ten patients with essential hypertension (19 determinations) ranged from 0·96 to 1·60 and from 0·68 to 1·44 respectively with mean values (±sem) of 1·21 ± 0·04 and 1·06 ± 0·05.
5. The renal vein to peripheral vein ratio of active renin on the affected side in 13 out of 17 patients with renovascular hypertension was above the range found in essential hypertension. Six of them also had an elevated ratio of inactive renin on that side, which indicated renal release of this form of renin into the circulation. But, in contrast to the renal vein to peripheral vein ratio of active renin, the mean value of the ratio of inactive renin on the affected side was not significantly higher than on the contralateral side. The results suggest a renal mechanism not only for controlling the total quantity of circulating renin but also for modulating its degree of activation.
Effect of Saralasin and Serum in Myohaemoglobinuric Acute Renal Failure of Rats
Authors: Bauereiss K. , Hofbauer K. G. , Konrads A. , Gross F. 
Published: August 2015

1. In rats deprived of food and water for 24 h acute renal failure was produced by the intramuscular injection of glycerol. Eight hours later plasma urea concentration had increased threefold despite a small rise in urine volume. Plasma concentrations of renin and renin substrate were elevated.
2. When saralasin, a competitive antagonist of angiotensin II, was infused for 8 h after glycerol injection, urine volume and plasma urea were similar to values in rats that had received an infusion of saline.
3. Administration of rat serum (4·5 ml h−1 kg−1) for 4 h suppressed plasma renin concentrations, but plasma urea increased to the same extent as in rats without serum.
4. When saralasin and serum were infused at the same time, urine volume, urine osmolality and solute excretion increased and the rise of plasma urea was diminished.
5. Saralasin has a protective effect against glycerol-induced acute renal failure only when volume is replaced concomitantly.