bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Insulin on Glucose Metabolism in Skeletal Muscle from Septic and Endotoxaemic Rats
Authors: Leighton Brendan , Dimitriadis George D. , Parry-Billings Mark , Bond Jane , de Vasconcelos Paulo R. L. , Newsholme Eric A. 
Published: August 2015

1. The effects of non-lethal bacteraemia or endotoxaemia on insulin-stimulated glucose metabolism were studied in isolated, incubated soleus muscle of rats after 24 and 48 h.
2. The insulin-stimulated rates of lactate formation and glycogen synthesis were similar in muscles isolated from control and bacteraemic rats.
3. Endotoxaemia increased the rates of lactate formation, at all levels of insulin, both at 24 h (∼ 32%) and 48 h (∼ 26%). Endotoxaemia did not alter the sensitivity of glycolysis to insulin.
4. Endotoxaemia decreased the rates of glycogen synthesis at all concentrations of insulin both at 24 h (∼ 39%) and 48 h (∼ 23%).
5. The increase in the rate of glycolysis was related in a dose-dependent manner to the amount of endotoxin given to the animals.
6. Endotoxaemia decreased plasma tri-iodothyronine levels (41%). However, the effects of endotoxaemia (48 h) on glucose metabolism in muscle are similar to those caused by hyperthyroidism. In hypothyroid rats, endotoxin administration increased the rates of glycolysis in muscle in vitro.
7. It is concluded that there are enhanced basal and insulin-stimulated rates of glycolysis in soleus muscle from endotoxaemic rats. This may be due to both increased glucose transport and decreased glycogen synthesis.
Role of Thromboxane A2 as a Mediator of Platelet-Activating-Factor-Induced Aggregation of Human Platelets
Authors: McCulloch R. K. , Summers J. , Vandongen R. , Rouse I. L. 
Published: August 2015

1. At present it is unclear whether platelet-activating-factor (PAF)-induced aggregation is mediated by thromboxane. To obtain further information about this event we have compared the affects of aspirin on platelet aggregation and secretion induced by PAF and collagen.
2. Collagen and PAF induced aggregation and secretion in human platelets in a dose-related manner.
3. Aspirin inhibited the magnitude of both platelet aggregation and secretion induced by PAF and collagen, but the degree of inhibition was much greater for collagen.
4. Aspirin strongly inhibited the aggregation rate of collagen-induced platelet aggregation, but had no measurable effect on the rate of PAF-induced aggregation.
5. Inconsistencies reported in previous studies of the effect of aspirin on PAF-induced platelet aggregation may be explained, in part, by the doses of PAF used and the method of inactivating cyclo-oxygenase (in vitro compared with in vivo).
6. Our results suggest that the initial events of PAF-induced aggregation are independent of thromboxane A2 formation and that thromboxane A2 plays only a minor role in the later phase of PAF-induced aggregation.
Time Course of Development of Changes in the Structure and Reactivity of Small Veins from Portal Hypertensive Rabbits
Authors: Juhl Claus Orloff , Jensen Lone Susanne , Mulvany Michael John 
Published: August 2015

1. Myographic and histological techniques were used to study the mechanical and morphological properties of oesophageal and mesenteric veins from rabbits subjected to 0, 4, 14 and 90 days of partial portal vein stenosis.
2. The stenosis caused an immediate increase in portal pressure from 10.5 mmHg (1.4 kPa) to 20.5 mmHg (2.7 kPa); the pressure returned to the control level by 90 days.
3. The lumen diameter of oesophageal veins was increased by 76% after 4 days and by 147% after 90 days, while that of the mesenteric veins was unchanged. The media thickness in both veins increased rapidly, reaching a maximum at 14 days (82%, oesophageal; 56%, mesenteric) and thereafter decreasing.
4. The contractility of oesophageal veins was transiently decreased (at 4 days), while that of the mesenteric veins was transiently increased (at 14 days).
5. In further experiments, sclerosing of the oesophagus, which is believed to restrict flow without reducing pressure, restricted the increase in lumen diameter of oesophageal veins caudal to the sclerosing site, but did not affect the media thickness.
6. The results suggest that, in oesophageal and mesenteric veins, portal pressure is a primary determinant of media thickness but not of lumen diameter.
Changes in the Haemodynamic Responses to Exercise, Posture and Nitrates after Treatment of Congestive Heart Failure with an Arteriolar Vasodilator
Authors: Thomas Phillip , Dixon Mark S. , Culling William , Sheridan Desmond J. 
Published: August 2015

1. Haemodynamic responses to exercise, posture and nitrates were measured before and after 8 weeks of therapy with an arteriolar smooth muscle specific calcium antagonist, nicardipine, in eight patients with congestive heart failure (New York Heart Association class II or III).
2. The acute haemodynamic effects of intravenous nicardipine before and after 8 weeks of oral therapy confirmed its vasodilating properties, with similar end-points to the initial response after the 8 week period.
3. After 8 weeks of oral therapy all patients improved by one New York Heart Association class and treadmill exercise duration was significantly increased. In contrast, sitting bicycle exercise duration was not prolonged, although, at the same peak workload, changes in cardiac output, stroke volume and systemic vascular resistance were significantly improved after 8 weeks of therapy.
4. Sublingual glyceryl trinitrate predominantly affected pulmonary vascular resistance before and after chronic therapy with nicardipine, although the effects were less marked after 8 weeks. In contrast, the systemic vascular effects of glyceryl trinitrate were significantly increased after 8 weeks of therapy with nicardipine.
5. Increased vasodilator responses to sublingual glyceryl trinitrate and exercise after chronic treatment with nicardipine, in the absence of significant residual vasodilatation at rest, suggests that indirect changes in systemic arterioles may accompany and possibly contribute to the clinical improvement in heart failure.
Prolonged Decrease in Blood Pressure after Atrial Natriuretic Peptide Infusion in Essential Hypertension: A New Anti-Pressor Mechanism?
Authors: Singer D. R. J. , Markandu N. D. , Buckley M. G. , Miller M. A. , Sugden A. L. , Sagnella G. A. , MacGregor G. A. 
Published: August 2015

1. To study the anti-hypertensive effects of atrial natriuretic peptide (ANP), eight patients with mild to moderate essential hypertension, on no treatment, were infused with α-human ANP (102–126) (37 pmol min−1 kg−1) or placebo for 60 min and observed for a further 4 h on the fifth day of low and high sodium diets in a randomized, cross-over study.
2. Plasma ANP levels increased over 30-fold into the high pathophysiological range during ANP infusion, but had returned to control values by 60 min after the end of infusion. With ANP infusion, there was a large decrease in supine blood pressure which was similar on both the low and high sodium intakes and was maximal 20–40 min after completion of the infusion. These reductions in blood pressure were sustained for a further 4 h after the end of ANP infusion and for 3 h after plasma ANP levels had returned to control values.
3. Maximal urinary sodium excretion increased 10-fold on the low sodium diet (negative sodium balance 20 mmol) and threefold on the high sodium diet (negative sodium balance 30 mmol) during ANP infusion; however, during the 4 h after infusion, urinary sodium excretion was below placebo values. During ANP infusion, packed cell volume increased significantly on both diets but returned to control values by 4 h after the end of infusion.
4. There were no significant changes in plasma renin activity compared with placebo during or after ANP infusion. However, plasma aldosterone was significantly greater than placebo values after the end of ANP infusion on both low and high sodium diets.
5. The sustained fall in blood pressure after ANP infusion appears to be unexplained by changes in sodium balance, packed cell volume and plasma ANP levels. These findings suggest that ANP may have a prolonged action on a pressor mechanism which remains to be defined.
Dependency of Microdissected Nephron Segments upon Oxidative Phosphorylation and Exogenous Substrates: A Relationship between Tubular Anatomical Location in the Kidney and Metabolic Activity
Authors: Torikai Shozo 
Published: August 2015

1. In order to examine the possibility of heterogeneity in the dependence of renal tubular cells upon oxidative phosphorylation and exogenous substrates, the effects of antimycin A and substrate deprivation on adenosine 5′-triphosphate (ATP) content were examined in isolated rat nephron segments in vitro at 37°C.
2. Antimycin A (5 μmol/l) caused varying decrements in cell ATP level within 5 min in the following order: proximal tubules &gt; cortical thick ascending limb of Henle's loop (cTAL) &gt; cortical collecting duct (cCD) in the cortex, and thin descending limb of Henle's loop (TDL) &gt; medullary thick ascending limb of Henle's loop (mTAL) &gt; outer medullary collecting duct (omCD) in the inner stripe of the outer medulla. In the thick ascending limb and the collecting duct, the segments located in the cortex were more sensitive than those in the medulla.
3. Substrate deprivation for 30 min markedly decreased the cell ATP content in cortical and medullary proximal tubules and also in medullary TDL, whereas it caused only a slight decrease in cTAL and mTAL with no change in cCD and omCD.
4. Media made hypertonic by the addition of 200 mmol/l NaCl under aerobic conditions, increased the requirement for exogenous substrates in TDL and mTAL, but not in omCD. This stimulation was seen to a lesser extent in media made hypertonic by the addition of mannitol instead of NaCl.
5. Taking into consideration a knowledge of rat kidney architecture and intrarenal gradient of oxygen partial pressure, it is likely that the observed dependency upon both oxygen and exogenous substrates in the renal tubular cells reflects adaptation of such cells to their anatomical location, and to the availability of those substances in situ. Furthermore, extracellular sodium concentration and osmolarity stimulate metabolic requirements to a different extent among the nephron segments.
Mast Cell Heterogeneity in Human Lung Tissue
Authors: Van Overveld F. J. , Houben L. A. M. J. , du Moulin F. E. M. Schmitz , Bruijnzeel P. L. B. , Raaijmakers J. A. M. , Terpstra G. K. 
Published: August 2015

1. In this study mast cells were found to comprise 2.1% of total cells recovered by enzymatic digestion of human lung tissue.
2. This mast cell population consisted of 79% formalin-sensitive, Alcian Blue-positive mast cells and 21% formalin-insensitive, Alcian Blue-positive mast cells.
3. By the use of centrifugal elutriation and subsequent Percoll gradient centrifugation, separate mixed cell populations could be obtained in which the mast cell constituents were either of the formalin-sensitive or -insensitive type.
4. Cell suspensions in which formalin-sensitive cells comprised 97% of mast cells contained approximately 1.34 pg of histamine per mast cell, whereas in preparations in which mast cells were 84% formalin-resistant the histamine content was approximately 4.17 pg of histamine per mast cell.
5. The histamine release upon anti-immunoglobulin E challenge of formalin-sensitive mast cells was greater than the release by formalin-insensitive mast cells.
6. After challenge with opsonized zymosan, only formalin-sensitive mast cells were able to release histamine.
7. Leukotriene C4 release was observed when formalin-sensitive mast cells were challenged with antiimmunoglobulin E. Formalin-insensitive mast cells showed no release of leukotriene C4.
8. Prostaglandin D2 release was observed when formalin-insensitive mast cells were challenged with antiimmunoglobulin E. Formalin-sensitive mast cells showed no release of prostaglandin D2.
Metabolic Changes in Human Liver Associated with Pre-Operative Intravenous Nutrition
Authors: Zeiderman M. R. , King R. F. G. J. , Young G. A. , McMahon M. J. 
Published: August 2015

1. This study examined the influence of pre-operative intravenous nutrition upon carbohydrate stores, glucose metabolism and protein synthesis in the liver of patients undergoing laparotomy.
2. Thirty patients with gastrointestinal cancer and weight loss (&gt;5 kg in 3 months) were randomized to receive a hospital diet only or a hospital diet plus intravenous nutrition (0.18 g of N + 125 kJ day−1 kg−1) for 3 or 7 days before laparotomy. Patients who had not lost weight received the hospital diet only and formed a control group.
3. Wedge biopsies of liver were obtained at laparotomy and analysed for glycogen concentration, the activity of three key enzymes of glucose metabolism, 6-phosphofructokinase (EC 2.7.1.11), fructose bisphosphatase (EC 3.1.3.11) and hexokinase (EC 2.7.1.1), and the capacity for protein synthesis.
4. Compared with controls and the hospital diet group, both phosphofructokinase and fructose bisphosphatase activity were reduced in patients who received intravenous nutrition, suggesting the utilization of glucose for glycogen synthesis with a reduction in the glycolytic flux. Consistent with these changes, patients who received intravenous nutrition had a significantly higher glycogen concentration compared with the control and hospital diet groups.
5. Maximal rates of protein synthesis were achieved after only 3 days of intravenous nutrition.
6. The provision of intravenous nutrition was associated with changes in hepatic metabolism suggestive of repletion of energy stores and a higher capacity for protein synthesis.
Rapid Correction of Hyponatraemia with Urea may Protect against Brain Damage in Rats
Authors: Van Reeth O. , Decaux G. 
Published: August 2015

1. Rapid correction of hyponatraemia in humans has been reported to be associated with central pontine myelinolysis (CPM). In patients with hyponatraemia related to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) we have rapidly corrected hyponatraemia by using urea, without observing clinical CPM. This led us to analyse the brain damage induced by hypertonic saline and by urea when used for the correction of hyponatraemia in a rat model of SIADH.
2. Severe hyponatraemia (serum Na+ &lt; 115 mmol/l) was produced in 28 rats. Seven rats were excluded from statistical analysis because they died during the correction of hyponatraemia, or because they were under- or over-corrected. Normalization of serum Na+ (135–146 mmol/l) was obtained in 48 h by hypertonic saline (group I, n = 7) or urea (group II, n = 8).
3. Despite similar correction of serum Na+ at 24 h and 48 h, all the rats treated with hypertonic saline presented severe brain damage, whereas those treated with urea were free of any brain damage. A third group of rats (n = 6) who spontaneously corrected their serum sodium level and presented mild hyponatraemia at 48 h (129 ± 5.2 mmol/l) were also free of any brain damage.
Comparison between Endogenous Digoxin-Like Immunoreactivity and 86Rb Uptake by Erythrocytes in Extracts of Human Plasma
Authors: Balzan S. , Montali U. , Genovesi-Ebert A. , Biver P. , Fantoni M. , Ghione S. 
Published: August 2015

1. To investigate endogenous cardiac glycoside-like compounds in plasma and their ability to inhibit the sodium pump, digoxin-like immunoreactivity [digoxin-like immunoreactive substance(s), DL1S] and 86Rb uptake by erythrocytes were measured in plasma extracts from normal adults, hypertensive adults and neonates.
2. DLIS levels in neonate plasma extracts were significantly higher than those found for normotensive or hypertensive adults. No difference was observed between normotensive and hypertensive subjects. DLIS was significantly increased when boiled plasma was extracted.
3. Extracts of boiled neonate and adult plasma inhibited 86Rb uptake. Instead, when boiling was omitted, no detectable inhibition was found in extracts of plasma from normotensive or hypertensive adult subjects. When present, the inhibition resulted from a depression of the ouabain-sensitive (sodium-pump-mediated) component, and, for the boiled neonate plasma only, also of the ouabain-resistant component. When the data from the different groups were pooled, a statistically significant inverse relationship between DLIS and erythrocyte 86Rb uptake was observed. Furthermore, in a subgroup of samples in which determinations were made before and after boiling in the same samples, an inverse correlation was found between changes in DLIS and changes in ouabain-sensitive (but not ouabain-resistant) 86Rb uptake.
4. Plasma extracts incubated with albumin at a physiological concentration significantly decreased (by approximately 20%) the inhibition of 86Rb uptake observed.
5. These findings support the existence of one or more endogenous compounds which both bind to antidigoxin antibodies and inhibit transmembrane cation transport. Part of this inhibition may, however, not involve the sodium pump. Furthermore, this chemically unidentified substance(s) may be bound to plasma proteins which partly reduce its action in vivo.
Alterations in Cerebrospinal Fluid Angiotensin II by Sodium Intake in Patients with Essential Hypertension
Authors: Kawamura Minoru , Kawano Yuhei , Yoshida Kaoru , Imanishi Masahito , Akabane Satoshi , Matsushima Yohkazu , Kuramochi Morio , Shimamoto Kazuaki , Ito Keiichi , Omae Teruo 
Published: August 2015

1. Angiotensin (ANG) levels were measured in the cerebrospinal fluid of 15 patients with essential hypertension on a high sodium diet for 1 week and on a low sodium diet for a further week. ANGs were determined using a system of extraction by Sep-Pak cartridges followed by h.p.l.c. combined with radioimmunoassay.
2. Sodium depletion resulted in increases of ANG II in the cerebrospinal fluid from 1.16 ± 0.38 (sem) to 1.83 ± 0.43 fmol/ml (P &lt; 0.01) and of ANG III from 0.65 ± 0.11 to 0.86 ± 0.15 fmol/ml (P &lt; 0.01).
3. The ANG II level in the cerebrospinal fluid was found to be unchanged and recovery of added ANG II was approximately 90%, even after incubation for 3 h, on both diets. Thus, it is unlikely that ANG II is produced or degraded in the cerebrospinal fluid in vitro.
4. There was no significant correlation between the cerebrospinal fluid and the plasma ANG II concentration on the low sodium diet.
5. These results suggest that the cerebrospinal fluid ANG II level increases with sodium depletion, and that the effect of the level of ANG II on the activity of the angiotensin-forming system in the central nervous system may be assessed by determination of ANG II in the cerebrospinal fluid in patients with essential hypertension.
Intracellular pH Clamping of Human Leucocytes: A Technique for Determination of Cellular Buffering Power and Na+/H+ Antiport Characteristics
Authors: Ng L. L. , Dudley C. 
Published: August 2015

1. A modified method is described for holding the intracellular pH of leucocytes at different values for prolonged periods of time.
2. Using ammonium sulphate at a final concentration of 8 mmol/l, the buffering power of leucocytes was measured at different internal pH values.
3. A marked dependence of buffering power on internal pH was found. As internal pH was lowered below 7.0, buffering power rose steeply. Above this value, buffering power remained approximately constant. This property may be one factor preventing intracellular acidosis under stress.
4. This method is also suitable for the study of Na+/H+ antiport activity. The addition of external Na+ to cells acid-loaded to an internal pH of 6.7 led to an ethyl isopropyl amiloride-sensitive 1:1 stoichiometric exchange of external Na+ for internal H+.
Effect of Aluminium on Superoxide Dismutase
Authors: Shainkin-Kestenbaum Ruth , Adler Andrew J. , Berlyne Geoffrey M. , Caruso C. 
Published: August 2015

1. The effect of Al3+ on superoxide dismutase in vitro was studied, since in uraemia there is excessive superoxide production and frequently an elevated serum Al3+ level. Thus, the protective role of superoxide dismutase is particularly important.
2. Al3+ in concentrations similar to those found in the serum of uraemic patients inhibits superoxide dismutase activity. The degree of inhibition is directly proportional to the Al3+ level.
3. The combination of excessive oxygen free radical production with an increased Al3+ level may contribute to a variety of complications, including aluminium dementia or initiation and promotion of carcinogenic processes, which are known to be more common in uraemic patients.
Endogenous Digoxin-Like Immunoreactive Factor and Digitalislike Factor Associated with the Hypertension of Patients Receiving Multiple Alkylating Agents as Part of Autologous Bone Marrow Transplantation
Authors: Graves Steven W. , Eder J. Paul , Schryber Susan M. , Sharma Kiran , Brena Anne , Antman Karen H. , Peters William P. 
Published: August 2015

1. Hypertension is a complication of autologous bone marrow transplantation when therapy includes multiple alkylating agents. We have sought to identify the factors underlying this hypertension. We measured weight, serum creatinine, plasma renin activity, aldosterone and digoxin-like immunoreactive factor (DL1F), by digoxin radioimmunoassay, in 18 patients. Plasma catecholamines were also measured in five patients.
2. Of the 18 patients studied, 15 became hypertensive. The variable most consistently associated with these individuals' hypertension was DLIF activity which was increased in 14 of the 15 hypertensive patients (P = 0.055, Fisher exact test). Serum creatinine was increased at some point in seven of the 15 hypertensive patients, weight was increased in five and plasma renin activity and aldosterone were increased in one. Catecholamines were not increased in any of the five patients in which they were measured.
3. The association between changes in mean arterial pressure (MAP) and changes in DL1F for the group as a whole was assessed by analysing one data pair per patient, representing the maximal MAP. This correlation was significant (r = 0.75, P = 0.001).
4. Within individual patients, changes in MAP and changes in serum DLIF concentrations were significantly correlated (r &gt; 0.50, P &lt; 0.05) in six of 15 hypertensive patients.
5. Digitalis-like factor (DLF) was measured by inhibition of (Na+,K+)-adenosine 5′-triphosphatase in five patients and DLF and DLIF were significantly correlated (r = 0.81, P = 0.0001). DLF and MAP were also significantly correlated (r = 0.59, P = 0.002).
6. This represents the first longitudinal study of the relationship between DLIF and blood pressure in hypertensive individuals, and the results suggest that DLIF may contribute to the increased blood pressure in some of these subjects.