bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fractional dextran and protein clearances in glomerulonephritis and in diabetic nephropathy
Authors: Ala-Houhala I. , Pasternack A. 
Published: August 2015

1. The renal clearance of dextran and protein of different molecular sizes has been measured in 42 proteinuric patients with diabetes and glomerulonephritis.
2. In both patient groups the fractional low molecular (radii 3.0–3.6 nm) dextran clearances were significantly decreased whereas the fractional high molecular (radii 5.1–7.8 nm) dextran clearances were increased as compared with the controls.
3. A porosity/charge index was constructed by calculating the ratio of fractional clearances of neutral to anionic macromolecules (θD36/θALB, θD5.1/θIgG). In diabetic patients the relation between the fractional clearances of neutral and anionic macromolecules was dependent on glomerular filtration rate.
4. It seems likely that the altered glomerular permeability in diabetic nephropathy is associated with a decrease of charge as renal function deteriorates. In glomerulonephritis the process is different and there is a high degree of variation from case to case.
A modified single breath method for estimation of cardiac output in humans at rest and during exercise
Authors: Al-Shamma Y. M. H. , Hainsworth R. , Silverton N. P. 
Published: August 2015

1. This study was undertaken to determine the accuracy of a modification of a single breath method for estimation of cardiac output. The technique incorporated a single rebreathing stage followed by a prolonged expiration. Cardiac output was determined from the O2 uptake and the instantaneous changes in O2 and CO2 in the expired gas during the prolonged expiration.
2. The mean values and the random errors (determined from the differences between pairs of estimates) of cardiac outputs in normal subjects at rest and exercise were 5.42 and ± 0.60 litres/min (2 sd, 60 pairs) and 14.1 and ±1.8 litres/min (40 pairs).
3. Larger random errors were obtained in a group of cardiac patients but, except in hypoxic patients, the mean values obtained by the single breath and the direct (Fick) methods were almost identical.
4. We conclude that our modification of the single breath method is simple to use and sufficiently reliable for use in humans both at rest and during steady states of light exercise.
Plasmin: A possible physiological modulator of the human platelet adenylate cyclase system
Authors: Adnot Serge , Ferry Nicolas , Hanoune Jacques , Lacombe Marie-Use 
Published: August 2015

1. Plasmin was recently reported to inhibit platelet aggregation [1]. We report here on the interaction of plasmin with the adenylate cyclase system of human platelets. Human plasmin caused a dose-and time-dependent increase in adenylate cyclase activity when added to a crude platelet membrane preparation. Both basal and prostaglandin E1-stimulated adenylate cyclase activity doubled in presence of plasmin. This stimulatory activity was shared by papain and α-chymotrypsin, but not by thrombin which displayed a slightly inhibitory effect.
2. Plasmin not only stimulated platelet adenylate cyclase activity, but also suppressed the GTP-dependent α2-adrenergic inhibition, thereby producing a five- to six-fold increased activity measured in the presence of adrenaline and GTP.
3. These effects of plasmin on the adenylate cyclase system were suppressed by the addition of the protease inhibitor leupeptin, and of soybean trypsin inhibitor, indicating that proteolysis mediated these effects.
4. We also examined the adenylate cyclase activity in membranes prepared from intact platelets incubated with increasing doses of plasmin. Incubation of platelets with plasmin concentrations as low as 0.25 mg/ml resulted in an irreversible increase in membrane adenylate cyclase activity and suppression of the adrenaline-mediated inhibition of enzyme activity.
5. These results suggest that the proteolytic stimulating effect of plasmin on the platelet adenylate cyclase system may account for the inhibition of platelet aggregation.
Decrease in human quadriceps muscle protein turnover consequent upon leg immobilization
Authors: Gibson J. N. A. , Halliday D. , Morrison W. L. , Stoward P. J. , Hornsby G. A. , Watt P. W. , Murdoch G. , Rennie M. J. 
Published: August 2015

1. Quadriceps muscle protein turnover was assessed in the post-absorptive state in six men immediately after the end of unilateral leg immobilization (37 ± 4 days) in a plaster cast after tibial fracture. A primed-constant intravenous infusion of l-[1-13C]leucine was administered over 7 h. Quadriceps needle biopsies, taken bilaterally at the end of the infusion, were analysed for muscle protein leucine enrichment with 13C.
2. Quadriceps muscle protein synthetic rate, calculated from the fractional incorporation of [13C]leucine into protein compared with the average enrichment of blood α-ketoisocaproate, was 0.046 ±0.012%/h in the uninjured leg, but was only 0.034 ±0.007%/h in the quadriceps of the previously fractured leg (P &gt; 0.05, means ± sd).
3. Muscle RNA activity (i.e. protein synthetic rate per RNA) fell from 0.27 ±0.08 μg of protein synthesized h−1 μg−1 of RNA in the control leg to 0.14 ±0.03 μg of protein synthesized h−1 μg−1 of RNA in the immobilized leg (P &gt; 0.02).
4. Immobilization was associated with a significant atrophy of type I muscle fibres (mean diameter 69.5 ±21 μm immobilized, 81.1 ±18 μm control, P &gt; 0.05), but no significant change occurred in type II fibre diameter. Mean quadriceps fibre volume calculated from the values for fibre diameter and percentage of each fibre type, was smaller in the injured leg by 10.6%; this value was near to the calculated difference in muscle thigh volume (calculated from thigh circumference and skin-fold thickness) which was less by 8.3%.
5. From estimated mean daily values for quadriceps protein synthetic rate (1.65 ±0.44%/day in the control legs and 1.22±0.28%/day in the injured legs) and change in fibre volume, mean daily muscle protein breakdown rates were calculated as 1.65%/ day and 1.53%/day respectively, suggesting that muscle protein breakdown was not enhanced and may have fallen.
6. The results suggest a decrease in muscle protein turnover during limb immobilization in man, with the decrement in muscle mass being due mainly to a substantial (25%) depression of muscle protein synthesis.
Lack of effect of atrial natriuretic peptide on vasopressin release
Authors: Ogawa K. , Arnolda L. F. , Woodcock E. A. , Hiwatari M. , Johnston C. I. 
Published: August 2015

1. This study was designed to investigate the effects of intracerebroventricular or intravenous atrial natriuretic peptide (ANP) on plasma arginine-vasopressin (AVP) levels, plasma renin activity (PRA), blood pressure (BP) and heart rate (HR) in conscious rats.
2. No changes were observed in plasma AVP levels and PRA after intracerebroventricular injection of ANP (0.3 nmol/kg). Also no changes were found in BP and HR after intracerebroventricular ANP injection in the dose range 0.01–0.3 nmol/ kg.
3. No significant changes were observed in plasma AVP levels after the intravenous administration of ANP at 2.5 nmol/kg to hydrated rats or at 0.1 nmol/kg and 2.5 nmol/kg to dehydrated rats, although the larger dose was sufficient to cause a small fall in BP.
4. Even after 30 min intravenous infusion of ANP at 0.1 nmol min−1 kg−1, a dose sufficient to produce very high plasma ANP levels, no change in plasma AVP could be detected, although haemodynamic changes were observed.
5. Intravenous ANP injection (2.5 nmol/kg) inhibited basal renin secretion in hydrated rats and also inhibited renin secretion which had been stimulated by prior dehydration.
6. From these studies in hydrated and dehydrated rats, there was no evidence that either intracerebroventricular or intravenous ANP administration affected AVP release in vivo.
The effect of sodium intake on rabbit renal prostaglandin E2 and thromboxane A2: dissociation from the renin–angiotensin system
Authors: Attallah Ahmad A. 
Published: August 2015

1. The effects of chronic alterations in dietary sodium intake on urinary prostaglandin (PG) E2 and thromboxane (TX) B2 was investigated in the rabbit.
2. Sodium restriction, over a 15-day period, reduced daily urinary PGE2 and TXB2 in concordance with urinary flow (V) and sodium excretion (UNa+V), but increased plasma renin activity (PRA) and plasma aldosterone concentration (PAC).
3. Sodium repletion, on the other hand, increased urinary PGE2 and TXB2 in proportion to the rise in V, but reduced PRA and PAC.
4. During both sodium diets PGE2 and TXB2 correlated positively with V and negatively with PRA.
5. It is concluded that chronic sodium intake produces opposite changes in the renal prostaglandin and the renin–angiotensin systems.
The iron content of finger-nails in iron deficient patients
Authors: Djaldetti M. , Djaldetti M. , Fishman P. , Hart J. 
Published: August 2015

1. The content of S, Ca, Fe, Cu and Zn in the finger-nails of 17 women with iron deficiency was examined by X-ray microanalysis and compared with that of 17 healthy women.
2. The values for all these elements were similar in both groups. The distribution curve for iron was also similar in both patients and controls. There was no correlation between the iron content of the finger-nails and the serum iron or haemoglobin levels.
3. It is suggested that the iron content of the finger-nails in iron deficient patients does not reflect their iron status.
Increased collagen synthesis and cross-link formation in the skin of rats exposed to vinyl chloride monomer
Authors: Knight Kenneth R. , Gibbons Rochelle 
Published: August 2015

1. Rats treated orally with vinyl chloride (30 mg/kg) daily for 2 years developed a syndrome which included thickening of the skin.
2. Analysis of the skin showed a 26% increase in collagen deposition per unit weight, and a corresponding 30% increase in the levels of glycosylated lysine and hydroxylysine. There was a significant increase in the amounts of the labile borohydride reducible cross-links, such as the intermolecular hydroxylysinonorleucine (+ 31%) and histidinomerodesmosine (+ 42%) as well as the intramolecular allysine aldol cross-links (+ 17%).
3. These results provide evidence that fibrosis of the skin is one of the pathological consequences of exposure to vinyl chloride.
Energy expenditure in non-insulin dependent diabetic subjects on metformin or sulphonylurea therapy
Authors: Leslie P. , Jung R. T. , Isles T. E. , Baty J. 
Published: August 2015

1. In the management of the non-insulin dependent diabetic patient, metformin often facilitates weight loss whereas sulphonylurea may predispose to weight gain. To investigate whether this is due to alterations in energy expenditure we have studied energy expenditure in seven non-insulin dependent diabetic subjects while on metformin or sulphonylurea therapy.
2. Three components of energy expenditure were measured by indirect calorimetry, namely resting metabolic rate and the thermic responses to infused noradrenaline and to a mixed constituent meal.
3. There was no significant difference in the resting metabolic rate on metformin (5.29 ± 0.41 kJ/min; mean ± se) compared with sulphonylurea (5.34 ± 0.34 kJ/min). The resting metabolic rate was also similar to predicted values for non-diabetic subjects (r = 0.96).
4. The thermic response to infused noradrenaline was similar on metformin (23.14 ± 1.87 kJ) and sulphonylurea (21.40 ± 2.98 kJ).
5. There was no significant difference in the thermic response to the meal on sulphonylurea (75.8 ± 7.5 kJ) or on metformin (86.8 ± 10.8 kJ; 95% confidence limits − 17 to + 39 kJ).
6. We conclude that in non-insulin dependent diabetic subjects metformin does not enhance energy expenditure overall, compared with sulphonylurea.
The gut in the acute phase response: Changes in colonic and hepatic enzyme activity in response to dermal inflammation in the rat
Authors: Hutton Charles W. , Corfield Anthony P. , Clamp John R. , Dieppe Paul A. 
Published: August 2015

1. Transient mild dermal inflammation was produced in rats by the subcutaneous injection of either carageenan or monosodium urate crystals. The activities of enzymes of the sialic acid metabolic pathway were measured in liver and colon at 8 h, 3 days and 7 days.
2. In both liver and colon the UDP-N-acetyl-d-glucosamine 2-epimerase and asialo-α1-acid glycoprotein sialyltransferase activities increased relative to controls while that of CMP-sialic acid hydrolase decreased. Similar changes occurred for both carageenan and monosodium urate crystals.
3. These results indicate that the acute phase response to a relatively minor inflammatory lesion causes significant changes in a distant and apparently unrelated tissue.
Acute effect of a thromboxane synthetase inhibitor on renal function in unanaesthetized sheep
Authors: Cumming Allan D. , Lindsay Robert M. , McDonald J. W. D. , Linton Adam L. 
Published: August 2015

1. Eleven healthy, unanaesthetized sheep were given either a single intravenous bolus infusion of U63,577A (Upjohn), a selective thromboxane synthetase inhibitor, at a dose of 30 mg/kg (group 1, n = 6), or vehicle alone (group 2, n = 5). Animals were maintained in metabolic cages during the study, and received 150 ml of water/h and 7.5 mmol of sodium/h as Ringers lactate by intravenous infusion for 24 h before and during the study. During two 1 h control urine collections via bladder catheter, urine volume and sodium excretion closely paralleled these infusion rates.
2. In the first hour after injection of U63,577A, there were significant two- to three-fold increases in urine volume, urinary sodium excretion and fractional sodium excretion, compared with the control collections. During the subsequent 4 h, urine volume, urinary sodium excretion, and fractional sodium excretion fell to values significantly lower than in the control period. Creatinine clearance was reduced 1, 2 and 4 h post injection and returned to control values at 5 h. Urinary excretion of thromboxane B2 was significantly reduced compared with control values during the 5 h after injection of U63,577A. Excretion of 6-keto-prostaglandin F1α did not change. Plasma renin activity was significantly increased 1, 3 and 5 h after injection of U63,577A. Vehicle controls showed no change in any of the above parameters.
3. The results indicate that in healthy conscious sheep, sodium and water replete, U63,577A has a transient but significant diuretic and natriuretic effect, followed by sodium and water retention and increased plasma renin activity. The results may reflect an antidiuretic/antinatriuretic effect of thromboxane A2, or possibly diversion of cyclic endoperoxides into formation of vasodilator/natriuretic prostaglandins. These effects might be exaggerated and/or modified in conditions where arachidonic acid metabolism is stimulated.
Ventilatory responses to inhaled carbon dioxide at rest and during exercise in man
Authors: Jacobi Margaret S. , Iyawe Vincent I. , Patil Chandu P. , Cummin Andrew R. C. , Saunders Kenneth B. 
Published: August 2015

1. Rapid steady-state CO2 responses were determined in six normal subjects at rest and five subjects at four different work loads up to 125 W, by injecting pure CO2 at constant flow into a small mixing chamber in the inspiratory limb of a breathing circuit.
2. The time course of the response of ventilation (V) and mean alveolar Pco2 (Paco2) was checked in separate experiments, where the flow rate of injected CO2 was changed abruptly and the effects were followed for 10 min.
3. V and Paco2 were measured every breath, and the results ensemble-averaged for each subject (two or three runs per subject) and then for the groups as a whole, in 30 s or 60 s time bins.
4. Paco2 during exercise was estimated by graphical reconstruction from the sloping alveolar plateau, and separately by the empirical equation of Jones, Robertson & Kane [1]. At rest, Paco2 was assumed equal to end-tidal Pco2 (Petco2).
5. With the constant inflow technique, 4 min was required to reach steady-state V and Paco2 during exercise, and 6 min at rest.
6. At rest, with 4 min steps (doubtful steady state) the averaged CO2 response was concave up. With 6 min steps the response was almost linear. In neither case was the deviation from linearity statistically significant.
7. During exercise, the averaged CO2 responses were essentially isocapnic at work loads greater than 75 W with either method of deriving Paco2.
Disturbance of acid–base balance in the young spontaneously hypertensive rat
Authors: Lucas P. A. , Lacour B. , McCarron D. A. , Drüeke T. 
Published: August 2015

1. The acid–base status of young spontaneously hypertensive rats (SHR) was compared with that of Wistar–Kyoto rats (WKY) in the steady state, after acid loading and after blood pressure had been maintained at normal levels from weaning. Whole blood ionized calcium was measured simultaneously.
2. In the prehypertensive stage (4 weeks of age), plasma bicarbonate was significantly lower in SHR than in WKY, while blood pH did not differ significantly.
3. After 6 weeks of age, blood pH and plasma bicarbonate were significantly lower in both anaesthetized and conscious SHR than in corresponding WKY. After 7 days administration of NH4Cl in the drinking fluid, both parameters decreased significantly in both strains and the difference in pH remained constant (0.05 pH unit, P &lt; 0.01).
4. In none of the groups investigated did non-pH-adjusted ionized calcium differ significantly between the SHR and WKY.
5. Prevention of the development of hypertension in SHR by hydralazine treatment from weaning did not increase pH or bicarbonate compared with untreated SHR, indicating that the metabolic acidosis in the SHR was not a consequence of raised blood pressure.
6. Disturbance in acid–base balance may be involved in the pathogenesis of raised blood pressure in this animal model of genetic hypertension.
Abnormal diurnal urinary sodium and water excretion in diabetic autonomic neuropathy
Authors: Bell G. M. , Reid W. , Ewing D. J. , Cumming A. D. , Watson M. L. , Doig A. , Clarke B. F. 
Published: August 2015

1. Diurnal patterns of urine output and sodium and potassium excretion were studied in 10 diabetic patients with and 10 without autonomic neuropathy, and in 10 normal subjects.
2. The diurnal patterns of excretion in the diabetic patients with autonomic neuropathy differed significantly from the two other groups, as a smaller proportion of the 24 h output of urine, sodium and potassium was excreted during the day and a larger proportion was excreted at night.
3. Similar changes were noted in the diurnal patterns of urinary kallikrein excretion in diabetic patients with autonomic neuropathy, and urinary kallikrein output correlated significantly with urine volume but not with urinary sodium excretion.
4. The diurnal patterns of excretion of urinary prostaglandin E2 and 6-keto-PGF1α were not significantly different in diabetic patients with autonomic neuropathy.
5. Nocturia was a common complaint in this group, and the number of nocturnal voidings correlated with night urine volume. There was no evidence of premature bladder emptying.
6. The changes observed in the day/night urine output and sodium excretion could not be explained by glycosuria, insulin regimens, impaired renal function or abnormal diurnal prostaglandin excretion; their possible relevance to the diurnal changes of urinary kallikrein excretion is discussed.
Dissociation between plasma atrial natriuretic peptide levels and urinary sodium excretion after intravenous saline infusion in normal man
Authors: Singer Donald R. J. , Shore Angela C. , Markandu Nirmala D. , Buckley Martin G. , Sagnella Giuseppe A. , Macgregor Graham A. 
Published: August 2015

1. Plasma immunoreactive atrial natriuretic peptide (ANP) and urinary sodium excretion were measured in six normal male subjects before, during and for 195 min after a 60 min infusion of 2 litres of saline (0.9% NaCl, 308 mmol of Na+).
2. During the saline infusion, there was a significant increase in plasma ANP and urinary sodium excretion and a significant decrease in plasma renin activity, aldosterone, albumin, creatinine and packed cell volume.
3. The maximal rise in mean plasma ANP occurred 15 min after stopping the infusion and the maximal rise in mean urinary sodium excretion in the collection period 30 min later.
4. Plasma ANP then decreased so that by the end of the study the level was the same as before the saline infusion. However, at this time, 195 min after the saline infusion was stopped, there was still a net positive sodium balance of 220 mmol and urinary sodium excretion remained significantly elevated.
5. Our results are compatible with the concept that increased ANP secretion may play a role in the immediate increase in sodium excretion after a saline load. However, they also suggest that other mechanisms may be more important for the longer term increase in sodium excretion.
Evidence for an inhibitor of leucocyte sodium transport in the serum of neonates
Authors: Morris J. F. , McEachern M. D. , Poston L. , Smith S. E. , Mulvany M. J. , Hilton P. J. 
Published: August 2015

1. In confirmation of previous studies, serum obtained from cord blood demonstrated endogenous digoxin-like immunoreactivity (EDLI). Sera from pregnant women in the third trimester also demonstrated EDLI, which disappeared after delivery.
2. Cord serum inhibited the total sodium efflux rate constant of a mixed leucocyte preparation when compared with the effect of control serum. This inhibition resulted from a depression of the ouabain-sensitive (sodium pump) component of the rate constant.
3. An ultrafiltrate of the serum (mol. wt. &lt; 30 000) also inhibited ouabain-sensitive leucocyte sodium transport when compared with filtrate obtained from control serum.
4. DHA-S Dehydroepiandrosterone sulphate (DHA-S) and cortisone, both present in high concentration in cord serum, demonstrated EDLI but did not affect leucocyte sodium transport in the cells of normal subjects.
5. DHA-S had no effect on sodium transport or vasoconstrictor activity in human omental resistance vessels.
6. It is concluded that EDLI of cord serum is associated with sodium transport inhibitory activity. This is unlikely to be attributable to DHA-S or cortisone.
Intravenously administered frusemide increases glomerular permeability
Authors: Ala-Houhala I. , Vapaatalo H. , Pasternack A. 
Published: August 2015

1. The effects of frusemide on glomerular permeability were investigated in eight proteinuric patients by measuring the fractional protein and dextran clearances and correlating these observations with changes in renal haemodynamics.
2. Frusemide increased significantly the fractional albumin and IgG clearances. The fractional dextran clearances of molecules with a radius ≥ 5.4 run also increased significantly after frusemide injection. Pretreatment with indomethacin partly inhibited the increments in clearances of macromolecules.
3. The changes in the fractional protein clearances correlated significantly with those of inulin clearance There was also a high degree of correlation between the changes in fractional protein clearances and prostanoid excretion.
4. The data obtained suggest that frusemide increases glomerular permeability by influencing the effective pores of the glomerular capillary wall. The increased permeability possibly is due to changes in prostanoid synthesis.