bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the Anterior Chamber of the Eye during Acute Hypoglycaemia in Humans
Authors: Hepburn D. A. , Clark C. V. , Pell A. C. H. , McIver B. , Frier B. M. 
Published: August 2015

1. The changes in the volume and depth of the anterior chamber of the eye during acute insulin-induced hypoglycaemia were examined in nine healthy non-diabetic subjects (aged 23–31 years). The dimensions of the anterior chamber of the eye were measured by a photogrammetric technique, with Polaroid photographs taken of the lower half of the mid-sagittal plane of the eye at an angle of 55° at a magnification of × 16. Photographs were taken before and at regular intervals after the induction of acute hypoglycaemia using an infusion of unmodified (soluble) insulin at 2.5 m-units min−1 kg−1. Plasma adrenaline was measured regularly throughout the study.
2. Plasma glucose fell from 4.5 ± 0.2 mmol/l (mean ± SEM) to a nadir of 1.0 ± 0.1 mmol/l (P &lt;0.01), which coincided with the onset of the acute autonomic reaction. Plasma adrenaline rose from 0.3 ± 0.1 nmol/l to a peak of 3.2 ± 0.6 nmol/l (P &lt;0.01) at 15 min after the autonomic reaction.
3. The volume of the anterior chamber decreased by 8.2% from 284.7 ± 21.5 μl at baseline to 264.5 ± 17.0 μl (P &lt;0.01) at the onset of the autonomic reaction. No significant alteration in axial anterior chamber depth was evident, but peripheral anterior depth decreased from 2.25 ± 0.20 mm at baseline to 2.07 ± 0.14 mm (P &lt;0.05) at the onset of the autonomic response. Pupillary constriction was demonstrated in all subjects, which was most marked at 10 min after the autonomic reaction (baseline 5.0 ± 0.2 mm versus 10 min after reaction 3.7 ± 0.2 mm, P &lt; 0.001).
4. This study has demonstrated an alteration in the dimensions and a reduction in volume of the anterior chamber of the eye in humans during acute insulin-induced hypoglycaemia. These changes in the anterior segment of the eye are probably mediated by autonomic mechanisms which are stimulated by hypoglycaemia.
Abnormalities in Skeletal Muscle Metabolism in Cyanotic Patients with Congenital Heart Disease: A 31P Nuclear Magnetic Resonance Spectroscopy Study
Authors: Adatia I. , Kemp G. J. , Taylor D. J. , Radda G. K. , Rajagopalan B. , Haworth S. G. 
Published: August 2015

1. Exercise tolerance is impaired in congenital heart disease. To examine the possible contribution of abnormalities in skeletal muscle bioenergetics, we used 31P nuclear magnetic resonance spectroscopy to investigate muscle metabolism in 10 subjects with congenital heart disease with cyanosis (median age 17.3 years) and in eight healthy age-matched control subjects. Spectra were collected from the gastrocnemius muscle at rest and during exercise and recovery.
2. In resting muscle there were significant elevations in cytosolic pH and in the cytosolic concentration of inorganic phosphate in the patients, and a strong positive correlation between cytosolic pH and blood haemoglobin concentration in all subjects.
3. During plantar flexion exercise the patients showed increased phosphocreatine depletion and cytosolic acidification over a shorter duration of exercise. The rise in calculated cytosolic ADP concentration was similar in both groups.
4. After cessation of exercise, the recovery half-times of phosphocreatine, ADP and phosphate were two to three times longer in the patients, and the initial rate of phosphocreatine resynthesis (a measure of the rate of mitochondrial ATP synthesis) was half the control value, consistent with a reduction in the effective maximum rate of oxidative ATP synthesis (expressed per volume of muscle). Also, recovery was faster in the young control subjects than in our earlier studies of older healthy control subjects.
5. The high phosphate concentration in resting muscle and the abnormalities found in exercise and recovery are consistent with a decrease in oxidative ATP synthesis due to reduced oxygen delivery by the blood in chronic hypoxaemia. The correlation between cytosolic pH and haemoglobin concentration remains to be explained.
1H-Nuclear Magnetic Resonance Studies of Human Synovial Fluid in Arthritic Disease States as An Aid to Confirming Metabolic Activity in the Synovial Cavity
Authors: Duffy J. M. , Grimshaw J. , Guthrie D. J. S. , McNally G. M. , Mollan R. A. B. , Spedding P. L. , Trocha-Grimshaw J. , Walker B. , Walsh E. 
Published: August 2015

1. A 1H-n.m.r. method was used to measure concentrations of valine, alanine, lactate, acetate, hyaluronan and lipids in synovial fluid obtained, during the normal course of examination, from the knee joints of patients attending rheumatology and orthopaedic clinics. Fluid was available from 16 patients with osteoarthritis, 18 patients with rheumatoid arthritis, four patients with meniscal tear and one patient each with systemic lupus erythematosis, mono-arthritis, synovitis and loose bodies. Four normal specimens were obtained for comparison.
2. Valine, alanine and acetate levels all showed a normal Gaussian distribution, reflecting the distributions within the serum of the sample population.
3. Lactate concentrations divided into two distinct patterns. At concentrations below 2.5 mmol/l the lactate levels showed a Gaussian distribution, reflecting the distribution in normal serum. The normal synovial fluid specimens belong to this distribution. Above 2.5-3.0 mmol/l, lactate levels were asymmetric in distribution with a long tail at higher concentrations. These high levels of lactate can be explained by the generation of lactate through anaerobic metabolism within the synovial cavity. This metabolic process is triggered by a general inflammatory condition such as in rheumatoid arthritis.
4. The distribution of n.m.r.-observable lipid concentrations in rheumatoid arthritis and osteoarthritis each shows a normal distribution and the mean concentration is significantly higher in rheumatoid arthritis.
5. An increased n.m.r.-observable hyaluronan concentration is associated with an inflammatory situation.
6. It is concluded that raised levels of lactate and n.m.r.-observable hyaluronan and lipids are useful markers to aid the clinical distinction between rheumatoid arthritis and osteoarthritis. The results of this study confirm rheumatoid arthritis as an inflammatory disease inducing higher metabolic activity within the synovial cavity.
Validity of Peak Expiratory Flow Rate Variability for the Diagnosis of Asthma
Authors: Jamison J. P. , McKinley R. K. 
Published: August 2015

1. The aim of this study was to determine the validity of various numerical indices of peak flow variability as tests for asthma.
2. Normal (n = 24) and asthmatic (n = 123) subjects aged 10-70 years were recruited from the community. Asthma was diagnosed by full clinical assessment and was active during the previous year. Subjects recorded their peak flow immediately after rising in the morning, at 18.00 hours and just before retiring at night for 12 days.
3. The most discriminating index was the highest peak flow variability which occurred within any 1 day during the 12-day recording period, calculated as the difference between the maximum and minimum peak flows expressed as a percentage of the minimum peak flow on that day (the proposed index). This index was &lt;20% (90th centile) in 96% of the normal subjects and ≧ 20% in 89% of the asthmatic subjects.
4. Standard indices of mean peak flow, the forced expiratory volume in 1.0 s and its responsiveness to salbutamol, had much lower sensitivities than peak flow variability.
5. It is concluded that numerical indices of peak flow variability are highly valid tests for asthma. Using an upper limit of normal of 20%, the proposed index of peak flow variability discriminates better than other indices between asthmatic and normal subjects.
Effects of Angiotensin II on Insulin Sensitivity: A Placebo-Controlled Study
Authors: Morris A. D. , Petrie J. R. , Anderson J. , Connell J. M. C. , Donnelly R. 
Published: August 2015

1. There is evidence that hyperinsulinaemia increases the aldosterone response to angiotensin II, and that angiotensin-converting enzyme inhibitor drugs enhance peripheral glucose utilization, but the direct effects of angiotensin II on insulin sensitivity have not been reported previously.
2. In a randomized, double-blind, placebo-controlled, cross-over study, 12 healthy male subjects attended on 3 study days for the evaluation of the effects of a subpressor (1 ng min−1 kg−1) and pressor (5 ng min−1 kg−1) infusion of angiotensin II on whole-body insulin sensitivity using the euglycaemic hyperinsulin-aemic clamp. Frequent measurements of blood pressure and heart rate were recorded and blood samples were collected for determination of serum insulin, C-peptide and K+ concentration, plasma renin activity and plasma angiotensin II concentration.
3. Plasma angiotensin II concentrations (means +SD) were 11+5 pg/ml after placebo, and 27+9 and 125+28 pg/ml after low and high dose angiotensin II, respectively. The higher dose of angiotensin II was associated with significant increases in blood pressure (e.g. 13 mmHg systolic blood pressure at 150 min) and serum aldosterone concentration. Whole-body insulin sensitivity was 10.5 + 2 mg of glucose min−1 kg−1 after placebo, and 10.5 +2.2 and 10.9+3.4 mg of glucose min−1 kg−1 after low and high dose angiotensin II (not significant).
4. Angiotensin II had no effect on hyperinsulinaemia-induced reductions in serum potassium and triacyl-glycerol concentrations.
5. Thus, acute infusion of angiotensin II for 3 h, with or without an increase in blood pressure, has no effect on whole-body insulin sensitivity.
Determination of Free Polyamines in Human Bile by High-Performance Liquid Chromatography
Authors: Hallak A. , Rosenberg R. , Gilat T. , Sömjen G. J. 
Published: August 2015

1. Polyamines are widely distributed in the body and may have cholesterol-nucleating activity in model bile and human bile. There are only partial and scant data available on the type of polyamines in human bile.
2. In this study methods for extraction of free polyamines, benzoylation and an h.p.l.c.-based method for the quantitative determination of putrescine, cadaverine, spermidine and spermine in bile are described. The h.p.l.c. methodology was validated and compared with separation on t.l.c. after dansylation.
3. The polyamine content of 11 gallbladder bile samples and 11 T-tube bile samples was analysed, all from patients with gallstones. Polyamines were found in three out of 11 gallbladder bile samples and eight out of 11 T-tube bile samples. Putrescine levels were 0.5-287 μmol/l and cadaverine levels were 2.4-645.4 μmol/l; these were considerably higher than spermine and spermidine levels.
4. As many of these gallstones bile samples were devoid of polyamines, it is questionable whether polyamines play an important role in cholesterol nucleation in human bile.
Extracellular Volume Expansion Inhibits Antidiuretic Hormone Increase during Positive End-Expiratory Pressure in Conscious Dogs
Authors: Kaczmarczyk Gabriele , Jörres Dinah , Rossaint Rolf , Krebs Martin , Unger Volker , Falke Konrad 
Published: August 2015

1. This study in conscious dogs examined the effects of extracellular volume expansion on plasma antidiuretic hormone, atrial natriuretic peptide and aldosterone concentrations, plasma renin activity, and haemodynamic and renal responses during controlled mechanical ventilation with 20 cmH2O positive end-expiratory pressure.
2. Twenty experiments (10 controls, 10 expansion experiments with 03 ml min−1 kg−1 body weight of a balanced electrolyte solution given intravenously throughout) were performed in five trained, conscious, tracheotomized dogs over 4 h: first and fourth hour, spontaneous breathing; second and third hour, 20 cmH2O positive end-expiratory pressure.
3. In the control experiments positive end-expiratory pressure increased plasma antidiuretic hormone concentration from 1.4 + 0.2 to 10.0 + 3.3 pg/ml, plasma aldosterone concentration from 113 + 19 to 258 + 58 pg/ml and heart rate from 77 + 5 to 94 + 5 beats/min. Positive end-expiratory pressure did not change plasma atrial natriuretic peptide concentration (55 + 5 pg/ml), plasma renin activity (2.6 + 0.4 pmol of angiotensin I h−1 ml−1) and mean arterial pressure 103 + 3 mmHg).
4. In the expansion experiments, positive end-expiratory pressure did not change plasma antidiuretic hormone concentration (1.1 + 0.1 pg/ml), plasma aldosterone concentration (25 + 2 pg/ml), plasma atrial natriuretic peptide concentration (82 + 8 pg/ml), plasma renin activity (0.8 + 0.15 pmol of angiotensin I h−1 ml−1), heart rate (92 + 6 beats/min) and mean arterial pressure (111 + 4 mmHg).
5. In the control experiments, urine volume, sodium excretion and fractional sodium excretion remained in a low range during positive end-expiratory pressure, whereas potassium excretion increased. In the expansion experiments, urine volume, sodium excretion and fractional sodium excretion increased continuously. Glomerular filtration rate was decreased during positive end-expiratory pressure in the control experiments when compared with the expansion experiments (3.4 + 0.3 versus 3.9 + 0.2 ml min−1 kg−1 body weight).
6. Arterial blood gases and plasma osmolality did not change in either protocol.
7. It is suggested that the striking increase in antidiuretic hormone may play a part in the circulatory control mechanisms that maintain mean arterial pressure during positive end-expiratory pressure when the extracellular volume is not expanded.
Inhibition of Nitric Oxide Synthesis in Forearm Vasculature of Insulin-Dependent Diabetic Patients: Blunted Vasoconstriction in Patients with Microalbuminuria
Authors: Elliott T. G. , Cockcroft J. R. , Groop P.-H. , Viberti G. C. , Ritter J. M. 
Published: August 2015

1. Microalbuminuria is a risk factor for cardiovascular disease in patients with insulin-dependent diabetes mellitus, and may be a marker of microvascular dysfunction including endothelial damage. The purpose of this study was to determine whether vasoconstrictor responses to NG-monomethyl-L-arginine, an inhibitor of endothelium-derived relaxing factor/nitric oxide biosynthesis, differ between healthy subjects and insulin-dependent patients with or without microalbuminuria.
2. Twenty-eight insulin-dependent diabetic patients (14 with normal albumin excretion, 14 with microalbuminuria) were studied under euglycaemic conditions, together with 14 healthy control subjects. Forearm vascular responses to brachial artery infusions of NG-monomethyl-L-arginine, sodium nitroprusside (an endothelium-independent nitrovasodilator) and carbachol (an endothelium-dependent vasodilator) were determined by strain gauge plethysmography.
3. Basal blood flow and vasodilator responses were similar in each group. NG-Monomethyl-L-arginine reduced blood flow by 41.3 + 2.3% (mean + SEM) in healthy control subjects, 34.0 + 3.4% in diabetic patients without microalbuminuria and 29.2 + 2.0% in diabetic patients with microalbuminuria. Diabetic patients differed from healthy subjects (P = 0.005), due to a difference between control subjects and microalbuminuric diabetic patients (P &lt;0.001). NG-Monomethyl-L-arginine did not influence nitroprusside responses but reduced carbachol responses in control subjects and normoalbuminuric diabetic patients but not in microalbuminuric diabetic patients.
4. These results provide evidence of abnormal endothelium-derived relaxing factor/nitric oxide biosynthesis in insulin-dependent diabetic patients with microalbuminuria.
Hydrogen Peroxide Generation in a Model Paediatric Parenteral Amino Acid Solution
Authors: Brawley Vince , Bhatia Jatinder , Karp Warren B. 
Published: August 2015

1. Parenteral amino acid solutions undergo photo-oxidation, which may be an important factor in total parenteral nutrition-associated hepatic dysfunction. Light-exposed parenteral solutions containing amino acids, in addition to vitamins and trace minerals, generate free radicals, which, in turn, may contribute to this type of injury. This study examined the characteristics of H2O2 production in a parenteral amino acid solution modelled on a commercially available paediatric parenteral amino acid solution.
2. The solution was exposed to light in the presence of riboflavin-5′-monophosphate (riboflavin), and peroxide formation in the presence and absence of catalase (H2O2 formation) was assayed using potassium iodide/molybdate.
3. Peak H2O2 production occurred at a light intensity of 8 μW cm−2 nm−1 in the 425–475 nm waveband and was linear to 2 h of light exposure. H2O2 production reached 500 μmol/l at 24 h.
4. H2O2 was directly related to a riboflavin concentration of up to 20 μmol/l and was maximal at 30 μmol/l.
5. H2O2 production was greatest in the amino acid/riboflavin solution at a pH of between 5 and 6.
6. Under the conditions of light exposure intensity, light exposure time, riboflavin concentration and pH found during the administration of parenteral nutrition in neonatal intensive care units, net H2O2 production occurs in solutions modelled on a paediatric parenteral amino acid preparation.
Renal Uric Acid Handling in Non-Insulin-Dependent Diabetic Patients with Elevated Glomerular Filtration Rates
Authors: Golik A. , Weissgarten J. , Cotariu D. , Cohen N. , Zaidenstein R. , Ramot Y. , Averbukh Z. , Modai D. 
Published: August 2015

1. Hypouricaemia is prevalent in diabetic patients. In most of the studies, the diabetic patients had some degree of diabetic nephropathy as evidenced by a decreased glomerular filtration rate and proteinuria. Therefore we studied renal uric acid handling in a group of type II diabetic patients with elevated glomerular filtration rates.
2. Eighteen type II diabetic patients with normal kidney functions and elevated glomerular filtration rate and a group of 18 healthy, age- and weight-matched control subjects, were studied. Serum fructosamine, creatinine and uric acid levels were determined. Twenty-four hour urine collections were obtained, and microalbumin, glucose, creatinine and uric acid, were measured.
3. The creatinine clearance was higher and the serum uric acid concentration was lower in the diabetic patients (P &lt;0.05). The 24 h urinary uric acid excretion and filtered uric acid load were similar in both groups. However, the derived parameters of uric acid clearance and fractional excretion were significantly higher in the diabetic patients (P &lt;0.002 and P &lt;0.05, respectively). A negative correlation was apparent between serum fructosamine concentration and serum uric acid concentration (r = −0.76). A positive correlation was found between serum fructosamine concentration and fractional uric acid excretion (r = 0.64) and between serum fructosamine concentration and filtered uric acid load (r = 0.66). A positive correlation was found between creatinine clearance and 24 h uric acid excretion (r = 0.61) and between creatinine clearance and filtered uric acid load (r = 0.82).
4. It appears that the hypouricaemia and hyperuricosuria in diabetic patients are associated with an elevated glomerular filtration rate and a net tubular reabsorptive defect that may herald the development of diabetic nephropathy.
Renal Tubular Protein Degradation of Radiolabelled Aprotinin (Trasylol) in Patients with Chronic Renal Failure
Authors: Rustom R. , Grime J. S. , Maltby P. , Stockdale H. R. , Jackson M. J. , Critchley M. , Bone J. M. 
Published: August 2015

1. The new method developed to measure renal tubular degradation of small filtered proteins in patients with normal renal function, using radio-labelled aprotinin (Trasylol) (R. Rustom, J. S. Grime, P. Maltby, H. R. Stockdale, M. Critchley, J. M. Bone. Clin Sci 1992; 83, 289–94), was evaluated in patients with chronic renal failure.
2. Aprotinin was labelled with either 99mTc (40 MBq) or 131I (0.1 MBq), and injected intravenously in nine patients, with different renal pathologies. 51Cr-EDTA clearance (corrected for height and weight) was 40 + 5.4 (range 11.2-81) ml min−1 1.73 m−2. Activity in plasma and urine was measured over 24–48 h, and chromatography on Sephadex-G-25-M was used to separate labelled aprotinin from free 99mTcO4− or 131I−. Renal uptake was measured for 99mTc-labelled aprotinin only.
3. The volume of distribution was 20.2 + 2.3 litres. Chromatography showed all plasma activity as undegraded aprotinin, and urine activity only as the free labels (99mTcO4− or 131I−).
4. As in patients with normal renal function, activity in the kidney appeared promptly, with 5.7 + 2.5% of the dose detected even at 5 min. Activity rose rapidly to 9.4 + 1.6% of dose after 1.5 h, then more slowly to 15.0 + 0.5% of dose at 4.5 h, and even more slowly thereafter, reaching 24.1 + 2.8% of dose at 24 h. Extra-renal uptake was again insignificant, and both 99mTcO4− and 131I− appeared promptly in the urine, with similar and uniform rates of excretion over 24 h.
5. Both tubular uptake at 24 h and the rate of tubular metabolism over 24 h were lower than in the patients with normal renal function studied previously, but only the rate of tubular metabolism was directly related to the glomerular filtration rate (r = 0.75, P &lt;0.02).
6. Correction for the reduced glomerular filtration rate yielded values for both tubular uptake (0.67 + 0.14 versus 0.32 + 0.03% of dose/ml of glomerular filtration rate, P &lt;0.005), and tubular metabolism (0.033 + 0.07 versus 0.015 + 0.001% of dose h−1 ml−1 of glomerular filtration rate, P &lt;0.005) that were higher by comparison with those for patients with normal renal function studied previously.
7. Fractional renal degradation of 99mTc-aprotinin (in h−1), derived from the mean rate of urinary excretion of the free isotope over a given interval, divided by the mean cumulative kidney uptake over the same interval, also fell steeply early, and then more slowly to 0.07 + 0.01 h−1 at 14.25 h (between 4.5 and 24 h).
8. It is concluded that the method described previously is also suitable in patients with chronic renal failure, allowing further research into renal disease progression.
Erythrocyte Ion Transport Alterations in Hypertriglyceridaemic Rats
Authors: Kuneš Jaroslav , Talib Hassan Karama Bin , DobešOvá Zdena , Vrána Antonín , Zicha Josef 
Published: August 2015

1. Hypertension appears to be associated with both abnormalities in ion transport and disturbances in lipid metabolism. The aim of the present study was to search for alterations in erythrocyte ion transport in hereditary hypertriglyceridaemic rats. This strain is characterized by a pronounced elevation of blood pressure which correlates with the plasma triacylglycerol level.
2. Erythrocyte Na+ content was elevated in hypertriglyceridaemic rats due to an increased ouabainresistant Na+ net uptake. This was caused not only by the acceleration of bumetanide-sensitive Na+ inward co-transport, but also by the augmentation of bumetanide-resistant Na+ inward leak. A moderate enhancement of bumetanide-sensitive Rb+ uptake was seen in hypertriglyceridaemic animals, but there were no changes in bumetanide-resistant Rb+ leak.
3. The plasma triacylglycerol level correlated positively not only with blood pressure (P &lt;0.001) but also with ouabain-resistant Na+ transport (P &lt;0.002), bumetanide-sensitive Na+ and K+ (Rb+) co-transport (P &lt;0.01 and P &lt;0.001, respectively), bumetanide-resistant Na+ leak (P &lt;0.02) and erythrocyte Na+ content (P &lt;0.05).
3. Thus the association of augmented ouabain-resistant Na+ transport with elevated blood pressure in this form of experimental hypertension might be mediated by genetic disorders of lipid metabolism.