bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced urinary excretion of leukotriene E4 by patients with multiple trauma with or without adult respiratory distress syndrome
Authors: Fauler Joachim , Tsikas Dimitrios , Holch Michael , Seekamp Andreas , Nerlich Michael L. , Sturm Johannes , Frölich Jürgen C.
Published: August 2015

1. The aim of the present study was to evaluate the systemic synthesis of cysteinyl leukotrienes in patients with multiple trauma. In order to do this, the urinary excretion of leukotriene E4 was assessed in the first 10 days after trauma.

2. Leukotriene E4 was unequivocally identified by g.c.-m.s. in the urine of healthy subjects and patients with multiple trauma after its conversion to 5-hydroxyeicosanoic acid. Leukotriene E4 was routinely isolated from 24 h urine samples by solid-phase extraction followed by reverse-phase h.p.l.c. and was subsequently quantified by r.i.a.

3. Healthy subjects excreted daily 10 ± 3 nmol of leukotriene E4/mol of creatinine (mean ± sem, n = 16) into urine.

4. Patients with multiple trauma who did not develop adult respiratory distress syndrome (n = 7) excreted 76.8 ± 6.7 nmol of leukotriene E4/mol of creatinine (mean ± sem) daily during the first 10 days after trauma, which was significantly (P < 0.01) more than did healthy subjects.

5. Excretion of leukotriene E4 was even more enhanced in three patients with multiple trauma who developed adult respiratory distress syndrome. Maximal amounts of 593 ± 185 nmol of leukotriene E4/mol of creatinine (mean ± sem) were excreted on day 9 after trauma by these three patients, which corresponds to a 7.7- and a 59-fold increase in excretion of leukotriene E4 compared with patients with multiple trauma who did not develop adult respiratory distress syndrome and healthy subjects, respectively.

6. The present study demonstrates an enhanced synthesis of cysteinyl leukotrienes in patients with multiple trauma, and suggests that cysteinyl leukotrienes are involved in the inflammatory reaction that follows multiple trauma.
Glutamine metabolism in the lungs of glucocorticoid-treated rats
Authors: Salleh M. , Ardawi M.
Published: August 2015

1. The effect of dexamethasone (30 μg day−1 100 g−1 body weight) on the regulation of glutamine metabolism was studied in the lungs of rats after 9 days of treatment.

2. Dexamethasone resulted in a negative nitrogen balance, and produced decreases in the blood concentrations of glutamine (32.3%) and glutamate (25.3%) but an increase in the blood concentration of alanine (33.9%).

3. Dexamethasone treatment increases the rates of production of glutamine and alanine by lung slices incubated in vitro.

4. Blood flow and arteriovenous concentration difference measurement across the lungs exhibited an increase in the net exchange rates of glutamine (131.6%) and alanine (113.2%) in dexamethasone-treated rats compared with corresponding pair-fed controls.

5. Dexamethasone treatment produced significant decreases in the lung concentrations of glutamine (47.2%), glutamate (30.9%) and 2-oxoglutarate (57.3%). The concentrations of alanine (52.1%), ammonia (24.7%) and pyruvate (43.7%) were increased.

6. The maximal activity of glutamine synthetase was increased (21.5%), but there was no marked change in that of glutaminase, in the lungs of dexamethasone-treated rats.

7. It is concluded that glucocorticoid administration enhances the rates of production of glutamine and alanine from lungs of rats (both in vitro and in vivo). This may be due to changes in efflux and/or increased intracellular biosynthesis of glutamine and alanine.
Renal haemodynamics of cyclosporin A nephrotoxicity in children with juvenile dermatomyositis
Authors: Peters A. M. , Heckmatt J. Z. , Hasson N. , Henderson B. L. , EL-Meleigy D. , Rose M. L. , Dubowitz V.
Published: August 2015

1. Renal haemodynamics were monitored over an average period of 19 months in 17 children being treated with cyclosporin A. Sixteen had juvenile dermatomyositis and one had chronic polyneuropathy. The dose of cyclosporin A ranged from 2.3 to 8.3 mg day−1 kg−1 (median 4.1 mg day−1 kg−1).

2. Glomerular filtration rate (expressed in terms of extracellular fluid volume), renal blood flow (expressed as a fraction of cardiac output) and filtration fraction were measured by using 99mTc-labelled diethylenetriaminepenta-acetate. They were compared with the dosage and trough blood levels of cyclosporin A, and, in 15 patients receiving prednisolone in addition to cyclosporin A, with steroid dosage.

3. All 17 children had a renogram performed 6 months after starting cyclosporin A treatment. Nine of them also had a renogram before starting cyclosporin A treatment (baseline study), while 13, in addition to their renogram 6 months after starting cyclosporin A treatment, also had at least one further renogram.

4. Glomerular filtration rate/extracellular fluid volume fell slightly but significantly from 0.009 (sd 0.0013) before starting cyclosporin A treatment to 0.0085 (0.002) min−1 (P < 0.01) 6 months after cyclosporin A treatment in the nine children who underwent a baseline study. This was accompanied by a significant (P < 0.001) fall in filtration fraction from 0.108 (0.015) to 0.088 (0.014). However, renal blood flow/cardiac output showed no change.

5. In the 13 children studied beyond 6 months after starting cyclosporin A treatment, there was no further significant overall change in any renal haemodynamic variable. However, throughout this period, trough blood levels of cyclosporin A, which ranged from 20 to 258 ng/ml (median 67 ng/ml), correlated inversely with glomerular filtration rate/extracellular fluid volume, but not with renal blood flow/cardiac output. Furthermore, although a weak correlation between filtration fraction and trough blood levels of cyclosporin A did not reach statistical significance, sequential changes in filtration fraction correlated significantly with corresponding sequential changes in glomerular filtration rate/extracellular fluid volume.

6. We conclude that the predominant mechanism of renal impairment at these relatively low trough blood levels of cyclosporin A is a reversible reduction in filtration fraction.
Fasting and post-prandial splanchnic blood flow is reduced by a somatostatin analogue (octreotide) in man
Authors: Cooper A. M. , Braatvedt G. D. , Qamar M. I. , Brown H. , Thomas D. M. , Halliwell M. , Read A. E. , Corrall R. J. M.
Published: August 2015

1. The effects of the subcutaneous administration of a long-acting somatostatin analogue (octreotide) or of placebo on the splanchnic blood flow response to a mixed solid meal has been examined in eight normal subjects by using a transcutaneous Doppler ultrasound technique. Each subject was studied on two occasions more than 1 week apart.

2. On the control day, feeding had a pronounced effect on both superior mesenteric artery and portal venous blood flows, causing a peak rise of 82% in superior mesenteric artery blood flow at 15 min and of 75% in portal venous blood flow at 30 min post-prandially (P < 0.001). Blood flows remained elevated 2 h after the meal. Pulse and blood pressure showed no significant changes from baseline.

3. Octreotide reduced fasting superior mesenteric artery blood flow by 59% (P < 0.05) and portal venous blood flow by 49% (P < 0.01) and blunted the normal post-prandial rise. Pulse and blood pressure did not change in response to either the injection or the ingestion of the meal.

4. Octreotide suppressed the release of insulin, glucagon and pancreatic polypeptide in response to feeding and resulted in post-prandial hyperglycaemia.

5. The mechanism of action of octreotide on splanchnic blood flow is uncertain. It may be mediated via a direct vascular effect or it may act via suppression of vasoactive intestinal hormones.
Atrial natriuretic peptide-induced relaxation of pre-constricted isolated rat perfused lungs: A comparison in control and hypoxia-adapted animals
Authors: Stewart A. G. , Thompson J. S. , Rogers T. K. , Morice A. H.
Published: August 2015

1. To further understand the vasodilator actions of atrial natriuretic peptide and its role in hypoxic pulmonary hypertension, we studied the effects of atrial natriuretic peptide in the isolated perfused rat lung during normoxic ventilation and after elevation of pulmonary artery pressure by either hypoxic ventilation or infusion of prostaglandin F2α. Control animals were compared with littermates that had become adapted to a 10% O2 environment for 3 weeks. Atrial natriuretic peptide was compared with atriopeptin I and atriopeptin III in order to study its structure-activity relationship.

2. Five experiments, each involving six control and six chronically hypoxic rats, were performed. During normoxic ventilation, atrial natriuretic peptide (30 ng-3 μg) produced a dose-dependent reduction in pulmonary artery pressure in chronically hypoxic rats, but had no action in the control animals.

3. Atrial natriuretic peptide dose-dependently abolished hypoxic pulmonary vasoconstriction to a greater extent in chronically hypoxic rats (EC50 98 ng) than in control rats (EC50 298 ng; P < 0.001). Bolus atrial natriuretic peptide (100 ng) produced a plasma concentration of 22.6 pmol/l at 1 min, which is within the pathophysiological range. Initial plasma atrial natriuretic peptide levels were 9.4 pmol/l in control animals and 27.4 pmol/l in chronically hypoxic rats.

4. Chronically hypoxic rats were more sensitive to atriopeptin I, atriopeptin III and atrial natriuretic peptide than were the control rats (P < 0.05). Atrial natriuretic peptide and atriopeptin III were equipotent and were 10 times more potent than atriopeptide I in both groups (P < 0.001).

5. Although atrial natriuretic peptide lowered pulmonary artery pressure in isolated perfused lungs pre-constricted with prostaglandin F2α (5 μg/min), there was no difference between the control and chronically hypoxic groups, and the EC50 296 ng in the chronically hypoxic rats was significantly (P < 0.001) less than that seen in the chronically hypoxic despite similar levels of induced constriction by the two stimuli.

6. A set dose of atrial natriuretic peptide produced the same percentage reduction in hypoxic pulmonary vasoconstriction despite differing levels of pre-constriction produced by ventilating with 7%, 5%, 3% or 0% O2. There was no change in the arterial partial pressure of O2 or the alveolar-arterial gradient after injection of atrial natriuretic peptide, suggesting that its effects are not due to a reduction in pulmonary oedema.

7. Atrial natriuretic peptide relaxes pre-constricted pulmonary arteries in the isolated perfused rat lung in a dose-dependent manner within the pathophysiological range. The greater action of atrial natriuretic peptide in chronic hypoxia could be due to its action at the new sites of hypoxic pulmonary vasoconstriction, the newly muscularized alveolar arteries which develop during adaptation to hypoxia.
Effect of glutamine-enriched total parenteral nutrition on septic rats
Authors: Ardawi M. Salleh M.
Published: August 2015

1. The effect of total parenteral nutrition with or without glutamine enrichment was studied in septic rats after 4 days of treatment.

2. Septic rats treated with glutamine-enriched total parenteral nutrition survived sepsis significantly better than other TPN-treated septic rats: the cumulative percentage of deaths over 4 days in septic rats treated with glutamine-enriched total parenteral nutrition was 25% compared with 55% in septic rats given total parenteral nutrition without glutamine and 70% in septic rats given glucose.

3. Glutamine-enriched total parenteral nutrition resulted in improved nitrogen balance in septic rats: the cumulative nitrogen balance over the 4 days of treatment was the least negative as compared with other groups of septic rats.

4. The rate of loss of intracellular glutamine in skeletal muscle was markedly decreased (P < 0.001) in response to glutamine-enriched total parenteral nutrition in septic rats.

5. The rate of protein synthesis was increased (21.2%) and the rate of protein degradation was decreased (35.5%) in response to glutamine-enriched total parenteral nutrition in septic rats.

6. It is concluded that the administration of glutamine-enriched total parenteral nutrition is beneficial to septic rats and possibly to septic patients.
Effect of insulin-induced hypoglycaemia on antral, pyloric and duodenal motility in fasting subjects
Authors: Fraser R. , Fuller J. , Horowitz M. , Dent J.
Published: August 2015

1. Hyperglycaemia alters gastric motility and delays gastric emptying. By contrast, there is little information regarding the effect of sub-normal blood glucose concentrations on gastric and, in particular, pyloric motility, although limited data suggest that hypoglycaemia is associated with accelerated gastric emptying despite an apparently increased basal pyloric pressure.

2. To determine the effects of hypoglycaemia on pyloric motility, we compared the effects of an intravenous injection of insulin (0.15 units/kg) with those of a placebo injection of saline in eight healthy human volunteers during phase I of the interdigestive migrating motor complex.

3. All subjects developed profound hypoglycaemia (mean blood glucose concentration 1.6 mmol/l compared with 4.0 mmol/l in the control group).

4. There was no significant difference in the number of antral (9 versus 7, P = 0.34), pyloric (3 versus 0, P = 0.31) or duodenal (21 versus 13, P = 0.42) pressure waves or in the basal pyloric pressure (0.3 mmHg versus 0.1 mmHg, P = 0.37) in the 45 min after insulin injection (hypoglycaemia) when compared with the 45 min after saline injection (euglycaemia). In both the euglycaemic and hypoglycaemic studies there was a time-dependent increase in the numbers of antral and duodenal waves consistent with the expected changes in the interdigestive migrating motor complex.

5. These results indicate that insulin-induced hypoglycaemia has no significant effect on pyloric motility during phase I of the interdigestive migrating motor complex.
Additive antiproteinuric effect of angiotensin-converting enzyme inhibition and non-steroidal anti-inflammatory drug therapy: A clue to the mechanism of action
Authors: Heeg Jan E. , de Jong Paul E. , de Zeeuw Dick
Published: August 2015

1. Both the angiotensin-converting enzyme inhibitor, lisinopril, and the non-steroidal anti-inflammatory drug, indomethacin, lower urinary protein excretion in renal disease and improve the selectivity of the residual proteinuria. Despite the clearly different renal haemodynamic profiles of the two drugs, we hypothesize that the antiproteinuric effect has a final common pathway that is a reduction in glomerular filtration pressure.

2. We studied the effects of lisinopril and indomethacin, separately and in combination, on urinary protein excretion, selectivity of proteinuria and renal haemodynamics in nine non-diabetic patients with overt proteinuria.

3. Urinary protein excretion was 5.4 ± 2.5 g/24 h in the control period. Lisinopril monotherapy lowered urinary protein excretion by 53 ± 26%. During indomethacin treatment urinary protein excretion was reduced by 63 ± 24%. After adding indomethacin to lisinopril, urinary protein excretion fell by a further 58 ± 23%, resulting in a 79 ± 17% decrease during combined therapy.

4. Although both lisinopril and indomethacin monotherapy appeared to result in an improvement in glomerular protein permselectivity, no further improvement was seen during the combination therapy.

5. The changes in proteinuria were associated with changes in glomerular filtration rate, which showed a pronounced fall with combination therapy. The renal haemodynamic profiles during the different therapies suggest a post-glomerular vasodilatation by lisinopril and a pre-glomerular vasoconstriction by indomethacin, and the combination of both during the combined treatment.

6. These data suggest a synchronous afterload and preload reduction of glomerular filtration pressure as the cause of the additive effect of the combination of angiotensin-converting enzyme inhibition and non-steroidal anti-inflammatory drug therapy in lowering glomerular filtration rate and proteinuria.
Evidence for heterogeneity of glycosylation of human renin obtained by using lectins
Authors: Hosoi Masayuki , Kim Shokei , Yamamoto Kenjiro
Published: August 2015

1. In this study, the carbohydrate structure of pure human renin was examined by using various lectins.

2. Pure renin could be separated into three forms by concanavalin A chromatography, a concanavalin A-unbound form, a loosely bound form and a tightly bound form, termed renins A, B and C, respectively. Renins A, B and C accounted for 3, 13 and 84%, respectively, of the purified renin. These forms were all present in individual human plasma and the relative proportions in plasma were 27 ± 3, 33 ± 4 and 39 ± 5% (means ± sem) for renins A, B and C, respectively (n = 5).

3. Each form, electroblotted on to the nitrocellulose sheet after gel electrophoresis, was incubated with five peroxidase-labelled lectins, lentil lectin, erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin, Ricinus communis agglutinin and peanut agglutinin. The protein was stained with 4-chloro-l-naphthol.

4. The staining pattern obtained with these lectins was significantly different among the three forms of human renin, confirming that they have different carbohydrate structures. Furthermore, the positive staining of human renin with erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin and Ricinus communis agglutinin was in contrast with the lack of binding of rat renin to these lectins.

5. These results indicate the renal secretion of differently glycosylated multiple forms of human renin. The carbohydrate structure of human renin appears to differ from that of rat renin.
Chloride influx in human leucocytes: A triple-isotope technique for the assessment of chloride transporters
Authors: Hogg M. , Ng L. L. , Davies J. E.
Published: August 2015

1. A novel triple-isotope method using 3H2O, [14C]-sucrose and 36Cl− for measuring initial Cl− uptake rates in human leucocytes that had been preincubated in 10% (v/v) autologous serum is described.

2. There was a marked dependence of Cl− influx on intracellular pH, the flux at an intracellular pH of 7.20 being about 11.2% of that at an intracellular pH of 7.56.

3. This Cl− influx was inhibited by 4,4-di-isothiocyanatostilbene-2,2-disulphonic acid in a dose-dependent manner. Half-maximal inhibition by 4,4-diisothiocyanatostilbene-2,2-disulphonic acid at an internal pH of 7.56 in the presence or absence of HCO−3 was 0.30 or 0.35 mmol/l, respectively.

4. Depletion of intracellular Cl− resulted in a 70.7% decrease in Cl− influx, whereas depletion of cellular ATP led to a 37.7% decrease in Cl− influx.

5. The phorbol ester 12-O-tetradecanoyl phorbol acetate at a concentration of 0.1 μmol/l reduced Cl− influx, especially the 4,4-di-isothiocyanatostilbene-2,2-disulphonic acid-sensitive component. This effect was independent of intracellular pH changes or Na+/H+ anti-port activity.
Mediators of the direct effects of amino acids on the rat kidney
Authors: El Sayed A. A. , Haylor J. , El Nahas A. M.
Published: August 2015

1. The response of the isolated rat kidney to a mixed amino acid solution was examined in the presence of three renal autacoid inhibitors, indomethacin (a cyclo-oxygenase inhibitor), sulpiride (a dopamine antagonist) and l-nitroarginine methyl ester (an inhibitor of nitric oxide synthesis).

2. Increasing the concentration of the mixed amino acid solution perfusing the kidney from 2 to 8 mmol/l (n = 6) produced a sustained increase in renal perfusate flow (P < 0.01) and reversed the time-dependent fall in [14C]inulin clearance (P < 0.01) demonstrated in kidneys perfused with 2 mmol/l mixed amino acids alone. A significant increase in the fractional sodium reabsorption and decrease in the fractional albumin excretion was also observed.

3. Indomethacin (10−4 mol/l, n = 6) produced partial (50%) inhibition of the effect of mixed amino acids on [14C]inulin clearance, but did not influence their ability to increase renal perfusate flow.

4. Sulpiride (0.7 μmol min−1 kg−1, n = 6) produced partial inhibition of the effect of mixed amino acids on both [14C]inulin clearance and renal perfusate flow by 60% and 50%, respectively. Sulpiride also entirely inhibited the reduction in fractional albumin excretion.

5. l-Nitroarginine methyl ester (10−4 mol/l, n = 6) completely inhibited the effect of mixed amino acids on [14C]inulin clearance, but did not inhibit the increase in renal perfusate flow, even though the basal vascular resistance was markedly enhanced. l-Nitroarginine methyl ester also inhibited the increase in fractional sodium reabsorption produced by the mixed amino acids.

6. It is concluded that prostaglandins, dopamine and nitric oxide may all have a role to play in the direct effect of mixed amino acids on renal function. This does not, however, preclude further modification by additional stimuli generated in vivo.
Effect of angiotensin-converting enzyme inhibitors on glomerular eicosanoid production in normotensive and spontaneously hypertensive rats
Authors: Harding P. , Stonier C. , Aber G. M.
Published: August 2015

1. This study was designed to examine the production of certain eicosanoids (prostaglandin E2), prostacyclin (as 6-keto-prostaglandin F1α) and thromboxane A2 (as thromboxane B2) by glomeruli isolated from normotensive Wistar-Kyoto and spontaneously hypertensive rats both before and after the administration of one of three angiotensin-converting enzyme inhibitors, captopril, enalapril or fosinopril, for 10 days.

2. Measurements of glomerular eicosanoid production were made under basal conditions and in the presence of excess exogenous arachidonic acid.

3. The production of prostaglandin E2, 6-keto-prostaglandin F1α and thromboxane B2 was greater by glomeruli from untreated spontaneous hypertensive rats (prostaglandin E2 2.24 ± 0.41, 6-keto-prostaglandin F1α 1.20 ± 0.13 and thromboxane B2 2.75 ± 0.43 ng 10 min−1 mg−1 of protein) than by those from Wistar-Kyoto rats (prostaglandin E2 1.41 ± 0.28, 6-keto-prostaglandin F1α 0.98 ± 0.11 and thromboxane B2 1.29 ± 0.24 ng 10 min−1 mg −1 of protein) under basal conditions. However, these differences only achieved statistical significance for thromboxane B2 (P < 0.01). Similar strain-related differences were noted in the presence of arachidonic acid.

4. The ratio of glomerular (prostaglandin E2 + prostacyclin)/thromboxane A2 production was significantly lower in spontaneously hypertensive rats than in their normotensive counterparts under basal conditions with values of 1.3 ± 0.18 and 2.2 ± 0.20, respectively (P < 0.01).

5. Angiotensin-converting enzyme inhibitors induced significant changes in the glomerular production of some eicosanoids, which differed both between strains and with the nature of the inhibitor.

6. All three angiotensin-converting enzyme inhibitors increased the ratio of glomerular (prostaglandin E2 + prostacyclin)/thromboxane A2 production in both strains of rat. This only achieved statistical significance in Wistar-Kyoto rats after treatment with enalapril (from 2.2 ± 0.20 to 5.3 ± 0.83, P < 0.01) and fosinopril (from 2.2 ± 0.20 to 7.9 ± 1.68, P < 0.01), and in spontaneously hypertensive rats after treatment with fosinopril (from 1.3 ± 0.18 to 4.2 ± 0.50, P < 0.005).

7. None of the angiotensin-converting enzyme inhibitors induced any change in the systolic blood pressure of Wistar-Kyoto rats, whereas captopril, enalapril and fosinopril induced significant and comparable reductions in that of spontaneously hypertensive rats from mean pretreatment values of 167.8 ± 3.2, 164.7 ± 2.5 and 175.2 ± 4.0 mmHg to 150.3 ± 2.7, 141.0 ± 2.2 and 154.0 ± 3.4 mmHg, respectively (P < 0.0005).

8. The effects of angiotensin-converting enzyme inhibitors on eicosanoid production by glomeruli from Wistar-Kyoto rats and spontaneously hypertensive rats appear to be unrelated to changes in systemic blood pressure or to the presence of a thiol group.
Glutamine and alanine metabolism in lungs of septic rats
Authors: Ardawi M. Salleh M.
Published: August 2015

1. The metabolism of glutamine and alanine in the lung was studied in rats made septic by a caecal ligation and puncture technique.

2. The blood glucose concentration was not significantly different in septic rats, but blood pyruvate, lactate, glutamine and alanine concentrations were markedly increased as compared with sham-operated rats. Conversely, blood ketone body and plasma cholesterol concentrations were significantly decreased in septic rats. Both plasma insulin and plasma glucagon concentrations were markedly elevated in response to sepsis. Sepsis resulted in a negative nitrogen balance.

3. Sepsis increased the rates of production of glutamine (52.5%, P <0.001), alanine (38.9%, P <0.001) and glutamate (48.6%, P <0.001) by lung slices incubated in vitro.

4. Sepsis increased lung blood flow by 27.6% (P <0.05). Blood flow and arteriovenous concentration difference measurement across the lung of septic rats showed an increase in the net exchange rates of glutamine (142.5%, P <0.001), alanine (129.4%, P <0.001), glutamate (100.9%, P <0.001) and ammonia (138.0%, P <0.001) as compared with sham-operated control rats.

5. Sepsis produced significant decreases in the lung concentrations of glutamine (36.8%), glutamate (20.8%), 2-oxoglutarate (64.8%) and AMP (18.3%). The lung concentrations of alanine (95.9%), ammonia (67.7%) and pyruvate (89.7%) were increased.

6. The maximal activities of glutamine synthetase (20.4%, P <0.05), phosphate-dependent glutaminase (18.9%, P <0.05) and alanine aminotransferase (25.5%, P <0.05) were increased, but there was no marked change in that of glutamate dehydrogenase, in the lungs of septic rats.

7. It is concluded that there are enhanced rates of production of glutamine and alanine from lungs of septic rats (both in vitro and in vivo). This may be due to changes in efflux and/or increased intracellular biosynthesis of both glutamine and alanine; these suggestions are discussed.
Variability in the measurement of nebulized aerosol deposition in man
Authors: Thomas S. H. L. , O'Doherty M. J. , Page C. J. , Nunan T. O.
Published: August 2015

1. This study was performed to determine the variability of two different scintigraphic methods of measuring pulmonary aerosol deposition, and to examine nebulizer particle size and drug output as potential sources of this variability.

2. A radioaerosol was produced from a 3 ml solution of 99mTc-labelled colloidal human serum albumin (0.05 mg, 37 MBq) using a standard jet nebulizer and air compressor. This was inhaled on three separate occasions by nine healthy male subjects. On one of these occasions, a further inhalation was performed to assess immediate repeatability using increased 99mTc activity (92 MBq).

3. Intrapulmonary aerosol deposition was measured with a γ-camera and was corrected for tissue attenuation and geometric distribution by using two different methods.

4. Estimated mean pulmonary deposition was 4.3% of the nebulizer dose using a lung phantom correction method, and 6.1% using a tissue attenuation method. For these two methods respectively variability between subjects (coefficient of variation) was 54 and 47%. For both methods, within-subject variability (coefficient of variation) was 37% between occasions and 23% within occasions.

5. The particle-size output of several nebulizers was highly reproducible (coefficient of variation < 4%), but the nebulizer mass and radionuclide output of two nebulizers was more variable (coefficient of variation 5–19%), and appeared to be an important contributor to the variability in pulmonary aerosol deposition.

6. The data presented here for pulmonary deposition, used with appropriate power statistics formulae, can be used to estimate the sample sizes required for comparative studies of lung aerosol deposition.
Oxidation-resistant variants of recombinant anti-leucoprotease are better inhibitors of human-neutrophil-elastase-induced emphysema in hamsters than natural recombinant antileucoprotease
Authors: Rudolphus A. , Heinzel-Wieland R. , Vincent V. A. M. M. , Saunders D. , Steffens G. J. , Dijkman J. H. , Kramps J. A.
Published: August 2015

1. Antileucoprotease, being sensitive to oxidative inactivation, can be produced by recombinant techniques. Via site-directed mutagenesis, two mutants of recombinant antileucoprotease were produced in which one or more of the oxidation-sensitive methionine residues were replaced by leucine: in rALP242, methionine-73 was replaced by leucine, and in rALP231, leucine was substituted for four methionine residues. In vitro, native antileucoprotease and the recombinant antileucoprotease preparations have similar inhibitory characteristics towards human neutrophil elastase. We hypothesized that replacement of methionine residues in the antileucoprotease molecule would result in a reduced oxidation sensitivity of the mutants.

2. After incubation of recombinant antileucoprotease and its mutants with increasing dosages of cis-platinum(II)diammine dichloride, we observed that native antileucoprotease and recombinant antileucoprotease were inactivated by this reagent to the same extent. Compared with this, rALP242 was less inactivated, whereas the inhibitory capacity of rALP231 was not influenced by cis-platinum(II)diammine dichloride at all.

3. After incubation of recombinant antileucoprotease, rALP242 and rALP231 with triggered polymorphonuclear leucocytes, which are thought to produce an excess of oxidants, we measured residual inhibitory activities towards human neutrophil elastase of 10%, 55% and 87%, respectively.

4. In vivo, the inhibitory effects of intratracheally administered rALP242 and rALP231 towards human-neutrophil-elastase-induced emphysema were significantly greater than that of recombinant antileucoprotease. There were no significant differences between the mutants. With respect to secretory cell metaplasia and haemorrhage, rALP231 tended to be a better inhibitor than recombinant antileucoprotease and rALP242.

5. We conclude that the recombinant antileucoprotease mutants are less sensitive to oxidation and consequently inhibit human-neutrophil-elastase-induced emphysema to a greater extent than recombinant antileucoprotease.
Effects of alcohol intake on plasma fatty acids assessed independently of diet and smoking habits
Authors: Burke V. , Croft K. D. , Puddey I. B. , Cox K. L. , Beilin L. J. , Vandongen R.
Published: August 2015

1. This study was designed to determine prospectively whether changing alcohol consumption influenced the proportion of plasma linoleic acid independently of diet or smoking habits, and to evaluate changes in the plasma linoleic acid concentration as a potential marker of changes in alcohol consumption.

2. Fasting plasma fatty acid profiles were investigated in 72 male drinkers who were randomly assigned to drink low-alcohol beer or to maintain their usual drinking habits for a period of 4 weeks.

3. At entry to the study, a higher alcohol intake was associated with lower proportions of plasma linoleic acid, arachidonic acid and dihomolinolenic acid and higher proportions of plasma palmitoleic acid, independently of changes in body mass index. Smoking habits were unchanged and there were no major changes in diet during the period of the intervention.

4. Because the plasma palmitoleic acid concentration has been suggested as a possible marker of ‘at risk’ drinking, we investigated plasma fatty acid concentrations as indicators of alcohol intake. The plasma palmitoleic acid concentration was not a useful discriminator. Indices determined using logistic regression and combining plasma apolipoprotein A-II and linoleic acid concentrations gave better discrimination than either variable alone.
Superoxide production by peripheral blood monocytes during sustained endotoxaemia in sheep
Authors: Polla Barbara S. , Clerc Josiane , Pittet Jean-François , Morel Denis R.
Published: August 2015

1. We have studied the time course of the numbers of arterial monocytes and their superoxide anion (O2−) production in a chronically instrumented sheep model of subacute endotoxaemia induced by a continuous intravenous infusion of Escherichia coli lipopolysaccharide (20 ng min−1 kg−1).

2. Four out of 11 animals died from irreversible respiratory and cardiovascular failure within 21 h of the start of lipopolysaccharide administration ('non-survivors'), whereas in the seven surviving sheep ('survivors') there was a persistence of decreased systemic vascular resistance, systemic hypotension, pulmonary hypertension, anorexia and lethargy.

3. O2− generation by isolated monocytes was measured by the O2− dismutase-inhibitable reduction of ferricytochrome c after stimulation with phorbol myristate acetate (100 ng/ml) or opsonized zymosan (3 mg/ml). Basal mean value of phorbol myristate acetate-stimulated O2− production was significantly (P = 0.008) higher for non-survivors (31.3 ± 8.8 nmol 30 min−1 10−6 cells; n = 4) than for survivors (6.2 ± 2.3 nmol 30 min−1 10−6 cells; n = 7).

4. For both survivors and non-survivors, monocyte counts and phorbol myristate acetate-stimulated O2− production increased over time to reach in survivors a plateau after 2 days of continuous lipopolysaccharide infusion. Similar results were obtained when monocytes were stimulated for O2− production with opsonized zymosan.

5. These results suggest that (1) increased O−2 production by monocytes and monocytosis appear with a precise, delayed time course during the development of subacute endotoxaemia in sheep; and (2) a high stimulated O2− production by monocytes before lipopolysaccharide administration may represent a predictive factor for the subsequent respiratory failure and outcome of endotoxaemia.
Damage to erythrocytes from long-term heat stress
Authors: Utoh Junichi , Harasaki Hiroaki
Published: August 2015

1. Erythrocytes are known to haemolyse in vitro at 48–50°C. We hypothesized that erythrocytes might be damaged at much lower temperatures if they are incubated for prolonged periods. Erythrocytes from healthy human donors (n = 7) were incubated at 37, 40, 42, 44, 46 or 48°C for 4–48 h. The haemolytic percentage and osmotic fragility were then measured by a modification of the method of Parpart et al. [9].

2. Significant haemolysis and increased fragility were not observed at any temperatures after incubation for 4 h. However, the haemolytic percentage increased after incubation for 24 h at 44°C (9.1 ± 4.9%, P<0.01), 46°C (52.4 ± 14.1%, P<0.01) and 48°C (98.0 ± 2.6%, P> 0.01) and after incubation for 48 h at 42°C (9.8 ± 4.5%, P<0.01) when compared with the values before heating (1.1 ± 0.9%). The osmotic fragility also increased after incubation for 24 h at and above 42°C.

3. Although heat-induced haemolysis and an increase in fragility have not been known to occur below 48°C, these were quite apparent after incubation for 24–48 h at only 42°C. This suggests that with regard to thermal effects, it is important to consider not only the temperature but also the duration of heating.
Membrane incorporation of non-esterified fatty acids and effects on the sodium pump of human erythrocytes
Authors: Dwight J. F. St. J. , Ribeiro A. C. Mendes , Hendry B. M.
Published: August 2015

1. Sodium pump function has been assessed by measurement of ouabain-sensitive 86Rb uptake in human erythrocytes after incorporation of palmitic, stearic, oleic and linoleic acids into the erythrocyte membrane. 14C-labelled fatty acids were used to measure membrane uptake of these substances.

2. For palmitic, oleic and linoleic acids, up to 1000 nmol of the fatty acid/ml of packed cells can be incorporated without causing significant haemolysis. For stearic acid, 270 nmol/ml of packed cells was incorporated in similar conditions. More than 88% of the fatty acid incorporated could be extracted with a 50 μmol/l fatty-acid-free albumin solution and was, therefore, in a non-esterified form in the erythrocyte membrane. The concentrations of palmitic, stearic, oleic and linoleic acids incorporated in these experiments represent a five- to ten-fold increase above the normal concentrations of these fatty acids in the membrane.

3. Up to 1000 nmol of palmitic, oleic and linoleic acids/ ml of packed cells and up to 270 nmol of stearic acid/ml of packed cells could be incorporated without a significant change in mean ouabain-sensitive 86Rb uptake with respect to control cells. Mean percentage changes in ouabain-sensitive 86Rb uptake for all these experiments were: palmitic acid, 3.7% (sd 11.4, n = 15); stearic acid, 4.0% (sd 5.7, n = 7); oleic acid, −4.8% (sd 19, n = 17); linoleic acid, 2.2% (sd 15.6, n = 19).

4. The demonstration of near-normal sodium pump activity in the presence of greatly elevated membrane levels of these fatty acids makes it extremely unlikely that they act as modulators of sodium pump function in vivo.
Isolation and purification of human biliary vesicles with potent cholesterol-nucleation-promoting activity
Authors: Miquel Juan Francisco , Rigotti Attilio , Rojas Eduardo , Brandan Enrique , Nervi Flavio
Published: August 2015

1. Cholesterol nucleation is a critical step in the formation of cholesterol gallstones. This nucleation takes place after aggregation and fusion of cholesterol-rich biliary vesicles, a process probably modulated by biliary proteins. The present study was conducted to identify specific proteins associated with native cholesterol-rich biliary vesicles and to explore their effect on the cholesterol-nucleation time of supersaturated artificial bile.

2. Hepatic bile was obtained from six patients with cholesterol gallstone disease. Biliary vesicles were isolated by ultracentrifugation and were purified by gel filtration chromatography. A small amount of protein (less than 1% by weight) remained associated with the purified cholesterol-rich biliary vesicles. The electrophoretic profile of these proteins was remarkably similar in all six patients, showing the presence of at least six polypeptides (of molecular mass from 52 to 200 kDa), five of them having carbohydrate residues (except the 52 kDa one). The effect of reconstituted biliary vesicle solutions, containing their specific vesicular proteins, on cholesterol-nucleation time was studied by mixing the vesicle solution with artificial supersaturated bile. A potent cholesterol-pronucleating activity, reflected in a 20–70% reduction in nucleation time, was present in the biliary vesicle solutions compared with control solutions having a similar lipid composition. The pronucleating activity disappeared on heating and was not detected in the micellar fraction containing the major proportion of biliary proteins.

3. These results indicate that cholesterol-rich biliary vesicles containing a unique and defined glycoprotein profile can be isolated and purified from human hepatic bile. The potent cholesterol-pronucleating activity of the biliary vesicles from patients with gallstones was unrelated to their lipid composition or cholesterol content. This activity was probably associated with their glycoprotein component, supporting the view that vesicular proteins may have a central role in the pathogenesis of cholesterol gallstone disease.
Acute administration of tumour necrosis factor-α or interleukin-1-α does not mimic the hypoketonaemia associated with sepsis and inflammatory stress in the rat
Authors: Evans Rhys D. , Ilic Vera , Williamson Dermot H.
Published: August 2015

1. Administration of tumour necrosis factor (cachectin) and of interleukin-1-α increased the plasma level of non-esterified fatty acids in fed rats, and in the case of interleukin-1-α the blood glycerol level was also increased, suggesting stimulation of adipose tissue lipolysis. There were parallel increases in the plasma level of triacylglycerols. Neither cytokine had significant effects on blood or liver total ketone body (acetoacetate plus 3-hydroxybutyrate) concentrations.

2. In starved rats, the higher plasma non-esterified fatty acid concentration was not increased further by the cytokines. The plasma triacylglycerol level was increased, although the absolute change was less than in fed rats. The ketonaemia associated with starvation tended to be increased by the cytokines, but this was only significant in the case of interleukin-1-α. Parallel changes occurred in hepatic ketone bodies.

3. It is concluded that tumour necrosis factor-α and interleukin-1-α are not responsible for the hypoketonaemia associated with sepsis or other inflammatory states.
Danazol induces resistance to both insulin and glucagon in young women
Authors: Bruce Raymond , Godsland Ian , Stevenson John , Devenport Maxeen , Borth Fiona , Crook David , Ghatei Mohammed , Whitehead Malcolm , Wynn Victor
Published: August 2015

1. Danazol elevates plasma insulin, plasma glucagon and serum low-density lipoprotein concentrations and reduces the serum high-density lipoprotein concentration.

2. Associations between these disturbances were studied in 17 women receiving danazol therapy for endometriosis. Eleven women underwent intravenous glucose tolerance tests with measurement of plasma glucose, insulin, C-peptide and glucagon concentrations and modelling analysis of intravenous glucose tolerance test concentration profiles. Six women underwent glucagon sensitivity tests. Serum concentrations of lipids and lipoproteins were measured in all cases.

3. Danazol reduced the fasting plasma glucose and insulin concentrations, but markedly raised the fasting plasma glucagon concentration. The insulin and C-peptide responses to the intravenous glucose tolerance test were increased twofold and the net decrement in glucagon concentration was increased tenfold. The glucose response to the intravenous glucose tolerance test was unaffected. Insulin sensitivity was reduced by 55%. Both first-phase plasma insulin responsiveness and net first-phase pancreatic insulin secretion were increased; insulin half-life was prolonged. The glucose response to the glucagon sensitivity test was reduced on treatment. The calculated low-density lipoprotein cholesterol level rose by 20%, whereas high-density lipoprotein cholesterol level fell by 47%. None of these changes in serum lipoprotein levels correlated with changes in insulin metabolism. In general, metabolic changes normalized after 3 months.

4. Danazol increases the sensitivity of pancreatic insulin and glucagon secretion to glucose. Danazol-induced insulin and glucagon resistance could be due to receptor down-regulation resulting from hypersecretion of insulin and glucagon.
Bleomycin-induced lung injury in rats selectively abolishes hypoxic pulmonary vasoconstriction: Evidence against a role for platelet-activating factor
Authors: McCormack David G. , Crawley David E. , Barnes Peter J. , Evans Timothy W.
Published: August 2015

1. The role of platelet-activating factor in the attenuated hypoxic pulmonary vasoconstriction associated with lung injury was evaluated using specific platelet-activating factor antagonists and an isolated perfused lung preparation.

2. Intratracheal bleomycin was administered to rats to produce acute lung injury. Animals received intratracheal saline (control), intratracheal bleomycin or the platelet-activating factor anatagonists BN 52021, WEB 2170 or WEB 2086 before and after bleomycin treatment. Forty-eight hours after intratracheal administration of bleomycin or saline the animals were killed.

3. The increases in pulmonary artery pressure during two periods of hypoxic ventilation and in response to 0.2 μg of angiotensin II were measured. Acetylcholine-induced vasodilatation after pre-constriction with prostaglandin F2α was also measured. To quantify lung injury, the wet/ dry ratio of lung weight was determined.

4. Bleomycin treatment attenuated the first and second hypoxic pressor responses by 93% and 77%, respectively, but not the pressor response to angiotensin II nor the vasodilator response to acetylcholine. BN 52021 plus bleomycin augmented the first hypoxic pressor response compared with bleomycin treatment alone, but the structurally unrelated platelet-activating factor antagonists WEB 2170 and WEB 2086 had no significant effect on the bleomycin-induced attenuation of hypoxic pulmonary vasoconstriction. None of the platelet-activating factor antagonists blocked the increase in the wet/dry lung weight ratio induced by bleomycin.

5. Bleomycin-induced lung injury selectively attenuates hypoxic pulmonary vasoconstriction, an effect that does not appear to be mediated by platelet-activating factor. The mechanism remains to be elucidated, but may involve destruction of the hypoxic ‘sensor’ within the respiratory tract.
Enhanced synthesis of neutrophil-activating peptide-I/interleukin-8 in active ulcerative colitis
Authors: Mahida Y. R. , Ceska M. , Effenberger F. , Kurlak L. , Lindley I. , Hawkey C. J.
Published: August 2015

1. We studied neutrophil-activating peptide-1/interleukin-8 in inflammatory bowel disease.

2. Mucosal levels of neutrophil-activating peptide-1/ interleukin-8 were significantly higher in patients with active ulcerative colitis [median 74.5 (range 17.7–450.8) pg/mg] than in patients with active Crohn's disease [10.4 (4–46.9) pg/mg; P<0.002] or in normal control subjects [10.4(4–16.6) pg/mg; P <0.002].

3. Circulating neutrophil-activating peptide-1/interleukin-8 was generally undetectable but there were higher levels of anti-neutrophil-activating peptide-1/interleukin-8 antibodies in patients with active ulcerative colitis [62.9 (3.4–239) ng/ml] than in patients with active Crohn's disease [5.9 (2.1–18.10) ng/ml; P <0.001] or in control subjects [6.1 (3.2–15.8) ng/ml; P <0.001].

4. Neutrophil-activating peptide-1/interleukin-8 may be of specific functional importance in mediating inflammation in ulcerative colitis.
Nitrogen absorption from isonitrogenous solutions of l-leucyl-l-leucine and l-leucine: A study in the isolated perfused rat small intestine
Authors: Plauth Mathias , Kremer Ingrid , Raible Armin , Stehle Peter , Fürst Peter , Hartmann Franz
Published: August 2015

1. We assessed the efficacy of nitrogen absorption from luminal L-leucine (1.2 and 12 mmol/l) and from isonitrogenous l-leucyl-l-leucine (0.6 and 6.0 mmol/l) in a preparation of vascularly and luminally perfused rat small intestine by measuring luminal leucyl-leucine disappearance and venous leucine appearance.

2. No intact dipeptide was found in the vascular perfusate. Leucine-nitrogen absorption, as judged by venous leucine appearance, was as efficient from free leucine (29 ± 3 and 245 ± 19 ng-atom min−1 g−1) as from leucyl-leucine (27 ± 4 and 211 ± 58 ng-atom min−1 g−1). It was not reduced in the presence of glycyl-l-proline or of the brush-border dipeptidase inhibitors alanine-β-naphthylamide and cilastatin.

3. After one passage of the whole small intestine, only trace amounts of dipeptide, but large amounts of free leucine, were detected in the luminal effluent. Peptidase activity in the luminal effluent was demonstrated in 100000 g supernatant and was inhibited by p-hydroxymercuribenzoate, but not by brush-border dipeptidase inhibitors.

4. We propose that nitrogen absorption from luminal leucyl-leucine may proceed predominantly via intraluminal peptide hydrolysis and subsequent transport of free leucine. Nevertheless, our findings and conclusions are at variance with previous observations and current opinion on intestinal handling of dipeptides, which may be due, in part, to the different methodological approach.
Ferrous ions detected in cerebrospinal fluid by using bleomycin and DNA damage
Authors: Gutteridge John M. C.
Published: August 2015

1. During pathological states of iron-overload or oxidant stress, low-molecular-mass iron can become available within extracellular fluids.

2. This iron would be converted to the ferrous state were it not for the protective anti-oxidant protein caeruloplasmin.

3. The ferrous-ion-oxidizing activity of caeruloplasmin rapidly converts ferrous ions back to the less reactive ferric state so that they can bind to available binding sites on transferrin.

4. Cerebrospinal fluids, however, often appear to contain low-molecular-mass iron, high levels of ascorbate and low levels of ferroxidase activity with little or no iron-binding capacity.

5. When iron ions are present in cerebrospinal fluid they are therefore likely to be in the ferrous state.

6. The development and application of an assay to speciate and measure ferrous ions in simple aqueous solution and their redox cycling activity in biological fluids is described.