bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vascular responsiveness and cation exchange in insulin-dependent diabetes
Authors: Halkin Amir , Benjamin Nigel , Doktor Hilary S. , Todd Sally D. , Viberti Giancarlo , Ritter James M. 
Published: August 2015

1. We measured forearm blood flow during brachial artery infusions of vasoconstrictors (angiotensin II and noradrenaline) and vasodilators (sodium nitroprusside and carbachol) in 16 healthy control subjects and in 18 patients with uncomplicated insulin-dependent diabetes mellitus. Erythrocyte Na+/Li+ countertransport and platelet Na+/H+ antiport activities were also measured.
2. The mean basal forearm vascular resistance was 22% lower in diabetic patients than in control subjects. The effects of each infusion on forearm vascular resistance were similar in diabetic patients and control subjects.
3. Erythrocyte Na+/Li+ countertransport activities were similar in diabetic patients and control subjects. Platelet Na+/H+ exchange (Vmax.) was approximately 40% greater in diabetic patients than in control subjects, whereas the Km for Na+ was similar.
4. In diabetic patients, but not in control subjects, the responses to sodium nitroprusside and carbachol correlated inversely with Na+/Li+ countertransport in erythrocytes (rs = −0.76, P &lt; 0.001, and rs = −0.66, P &lt; 0.005, respectively), but not with Na+/H+ exchange in platelets.
Muscle composition in relation to age and sex
Authors: Forsberg A. M. , Nilsson E. , Werneman J. , Bergström J. , Hultman E. 
Published: August 2015

1. A method is described enabling the determination of fat, water, electrolytes, protein, DNA, RNA and total creatine in a single sample of human muscle obtained by the percutaneous needle-biopsy technique. The amino acid content can also be analysed in the same muscle sample.
2. Fifty healthy subjects were studied: 29 between 19 and 40 years of age, 11 between 41 and 60 years of age, and 10 between 61 and 85 years of age. The two groups aged less than 60 years showed only marginal differences in muscle composition, whereas the highest age group showed increases in muscle fat content in relation to tissue weight and decreases in alkali-soluble protein content in relation to both tissue weight and tissue DNA content. Also, potassium, magnesium, total creatine and RNA contents were decreased in this age group when related to tissue DNA content. When alkali-soluble protein was used as a reference base, only magnesium content was decreased.
3. A comparison was also made between female (n = 23) and male (n = 18) subjects in the age groups below 60 years. Differences observed included a higher fat content in female muscle, and an increase in total creatine content in relation to tissue weight. The alkali-soluble protein content was lower per muscle cell in the females when calculated on the basis of DNA content.
4. The results show that in the assessment of muscle constituents, age and sex must be taken into account.
Elevated endothelial-cell-stimulating angiogenic factor activity in rodent glycolytic skeletal muscles
Authors: Cooper R. G. , Taylor C. M. , Choo J. J. , Weiss J. B. 
Published: August 2015

1. Capillary density is greater in skeletal muscles comprised of predominantly oxidative (type I) fibres than in those comprised of mainly glycolytic (type II) fibres. In order to investigate further the angiogenic mechanisms involved in muscle capillarization, endothelial-cellstimulating angiogenic factor activities in various rodent skeletal muscles were compared.
2. Eleven untrained adult male Wistar rats were killed and the predominantly oxidative (type I) muscles, soleus and heart, the predominantly glycolytic (type II) muscle, extensor digitorum longus, and the mixed-fibre muscle, gastrocnemius, were removed. Each sample was separately homogenized and centrifuged and the supernatants were diafiltered to isolate the low-molecular-mass fraction containing endothelial-cell-stimulating angiogenic activity. This was assayed for its ability to activate latent collagenase and was expressed as units, where 1 unit represents the percentage activation of the enzyme h−1 (mg of protein in the supernatant)−1.
3. The results (medians and ranges) demonstrated significantly greater endothelial-cell-stimulating angiogenic factor activity in extensor digitorum longus muscle (2.14 units, 0.62–2.87 units, n = 13) than in soleus (0.82 units, 0.59–1.79 units, n = 15), gastrocnemius (0.34 units, 0.28–0.40 units, n = 4) or heart (0.43 units, 0.16–0.52 units, n = 11) (P&lt; 0.01 for each) muscle.
4. These findings suggest that endothelial-cell-stimulating angiogenic activity in muscle is either inversely or not related to the local capillary density, which may be at or near a maximum in physiologically contracting, predominantly oxidative muscles.
Aluminium: Gastrointestinal absorption and renal excretion
Authors: Lote C. J. , Saunders H. 
Published: August 2015

INTRODUCTION: SOURCES AND BIOAVAILABILITY OF ALUMINIUM
Aluminium is the most abundant metal and constitutes 8% of the earth's crust. It is a normal constituent of vegetable and animal tissues and is present in raw untreated water. In domestic tap-water supplies, aluminium may be present in high concentrations either from its presence in raw water or, more commonly, as a result of its use during the water-purification process. Aluminium in the metallic form is widely used for both industrial and domestic purposes, and a variety of aluminium salts are used in foods, fluids, cosmetics and medications.
The toxicity of aluminium in patients with renal failure is now well documented, and dialysis encephalopathy, osteomalacia and anaemia are recognized hazards in such patients if aluminium is not excluded from dialysis fluids and medications. The safe levels of aluminium in food, water, medications and infusion fluids for subjects with normal renal function are unknown, but aluminium has been implicated as causative agent in a number of dementia diseases, including Alzheimer's disease.
Plasma and tissue kallikrein–kinin systems during acute administration of frusemide in normotensive and hypertensive humans
Authors: Öhman K. Peter , Karlberg Bengt E. 
Published: August 2015

1. This study aims to further elucidate the role of the tissue and plasma kallikrein-kinin systems in blood pressure, electrolyte and volume homoeostasis. Components thereof and of the renin-angiotensin-aldosterone system were measured in conjunction with frusemide administration, in normotensive subjects and in patients with primary hypertension.
2. Frusemide increased plasma pre-kallikrein, angiotensin II and aldosterone concentrations and plasma renin activity, whereas the plasma level of tissue kallikrein remained unchanged. Basal values and the induced changes were similar in both groups.
3. Frusemide increased the urine volume and the excretion of Na+, K+, Mg2+, Cl−, aldosterone, prostaglandin E2 and tissue kallikrein. These changes were similar in both groups, but the total tissue kallikrein excretion was significantly lower in the hypertensive patients. Excretion of electrolytes and hormones was also measured during three 24 h urine collection periods and did not differ between the two groups.
4. Thus, acute administration of frusemide to hypertensive patients and normal subjects increased the plasma level of pre-kallikrein, possibly indicating less activation to kallikrein and subsequently less kinin generation in the blood stream. This also suggests a role for the plasma kallikrein-kinin system in the regulation of vascular tone and blood volume. Circulating tissue kallikrein does not seem to be acutely involved.
5. Urinary excretion of kallikrein is reduced in patients with primary hypertension after the administration of frusemide, apparently without affecting the renal excretory response.
Effects of hypothyroidism on glucose and glutamine metabolism by the gut of the rat
Authors: Ardawi M. Salleh M. , Jalalah Sawsan M. 
Published: August 2015

1. The metabolism of glucose and glutamine was studied in the small intestine and the colon of rats after 4–5 weeks of hypothyroidism.
2. Hypothyroidism resulted in increases in the plasma concentrations of ketone bodies (P &lt; 0.05), cholesterol (P &lt; 0.001) and urea (P &lt; 0.001), but decreases in the plasma concentrations of free fatty acids (P &lt; 0.05) and triacylglycerol (P &lt; 0.001). These changes were associated with decreases in the plasma concentrations of total triiodothyronine, free tri-iodothyronine, total thyroxine and free thyroxine.
3. Hypothyroidism decreased both the DNA content (by 30.5%) and the protein content (by 23.6%) of intestinal mucosa, with the protein/DNA ratio remaining unchanged. The villi in the jejunum were shorter (P &lt; 0.05) and the crypt depth was decreased by about 26.5% in hypothyroid rats.
4. Portal-drained visceral blood flow showed no marked change in response to hypothyroidism, but was accompanied by decreased rates of extraction of glucose, lactate and glutamine and release of glutamate, alanine and ammonia.
5. Enterocytes and colonocytes isolated from hypothyroid rats showed decreased rates of utilization and metabolism of glucose and glutamine.
6. The maximal activities of hexokinase (EC 2.7.1.1), 6-phosphofructokinase (EC 2.7.1.11), pyruvate kinase (EC 2.7.1.40), citrate synthase (EC 4.1.3.28), oxoglutarate dehydrogenase (EC 1.2.4.2) and phosphate-dependent glutaminase (EC 3.5.1.2) were decreased in intestinal mucosal scrapings from hypothyroid rats. Similar decreases were obtained in colonic mucosal scrapings (except for citrate synthase and oxoglutarate dehydrogenase) from hypothyroid rats.
7. It is concluded that hypothyroidism decreases the rates of utilization of glucose and glutamine (both in vivo and in vitro) by the epithelial cells of the small intestine and colon. This may be caused by changes in protein turnover and/or the maximal activities of key enzymes in the pathways of glucose and glutamine metabolism in these cells.
The pre-term guinea-pig: a model for the study of neonatal lung disease
Authors: Kelly F. J. , Town G. I. , Phillips G. J. , Holgate S. T. , Roche W. R. , Postle A. D. 
Published: August 2015

1. Research into the pathogenesis of acute and chronic neonatal lung disease has been hampered by the lack of a suitable small-animal model of prematurity. We describe such a model that has been developed and validated in the guinea-pig.
2. Pre-term guinea-pigs delivered by Caesarian section at 65 days gestation (normal gestation 68 days) exhibited transient respiratory distress. The survival of pre-term animals was lower than that of term animals after exposure to 95% O2 (pre-term 42% versus term 79% at 96 h, P &lt; 0.05).
3. Pulmonary histology in pre-term animals exposed to both 21% O2 and 95% O2 revealed evidence of acute lung injury with atelectasis, pulmonary oedema, fibrin deposition and inflammatory cell infiltration. No evidence of lung injury was observed in term animals exposed to 21% O2, whereas those exposed to 95% O2 showed a similar, but less pronounced, injury to that seen in preterm pups.
4. The protein concentration in bronchoalveolar lavage fluid was similar in pre-term and term animals exposed to 95% O2, but neutrophil numbers in bronchoalveolar lavage fluid tended to be greater in preterm pups.
5. Elastase-like activity, measured against succinyl-1-trialanine p-nitroanilide, was higher in bronchoalveolar lavage fluid from control pre-term animals compared with that from control term animals. Exposure to 95% O2 increased the elastase-like activity significantly in both groups. The majority of the elastase-like activity was EDTA-sensitive and thus is possibly due to metallo-elastase. Fractionation of bronchoalveolar lavage fluid indicated that the elastase-like activity was associated with a high-molecular-mass complex. Lipase treatment reduced the activity of this fraction and generated a new 40 kDa fraction.
6. We conclude that the pre-term guinea-pig is more susceptible than the term animal to lung injury after O2 exposure and thus represents a appropriate small-animal model in which to investigate the pathogenesis of acute and chronic lung injury in the pre-term infant.
Renal expression of intercellular adhesion molecule-1 in different forms of glomerulonephritis
Authors: Lhotta K. , Neumayer H. P. , Joannidis M. , Geissler D. , KöNig P. 
Published: August 2015

1. Expression of intercellular adhesion molecule-1 was investigated in five normal kidneys and 47 renal biopsies with the use of monoclonal antibody 7F7 and immunoperoxidase staining.
2. In the normal kidney, intercellular adhesion molecule-1 was expressed on endothelial cells of glomerular and peritubular capillaries, on Bowman's capsule, on some interstitial cells and weakly in the mesangium.
3. Increased glomerular staining was detected in early cases of rapidly progressing glomerulonephritis (5/8) and in some cases of non-IgA mesangioproliferative glomerulonephritis (5/9), IgA nephropathy (3/5), Henoch-Schoenlein purpura (2/2), lupus nephritis (5/6) and focal segmental glomerulosclerosis (1/3). A decrease in intercellular adhesion molecule-1 expression was noted in advanced rapidly progressive glomerulonephritis (3/8), two cases of membraneous nephropathy, one severe mesangioproliferative glomerulonephritis biopsy, the two membranoproliferative glomerulonephritis biopsies and in sclerotic loops in focal segmental glomerulosclerosis.
4. Expression de novo on tubular epithelial cells occurred in rapidly progressive glomerulonephritis, in membranoproliferative glomerulonephritis, and to a lesser extent in some cases of membranous nephropathy, minimal change disease, IgA nephropathy, focal segmental glomerulosclerosis, a severe case of mesangioproliferative glomerulonephritis and in the mixed essential cryoglobulinaemia case. In 63% of positive tubuli, intraluminal cells which expressed CD18, the common β-chain of leucocyte-function-associated antigen-1, Mac-1 and p150,95, were present.
5. Intercellular adhesion molecule-1 was also found on the majority (59%) of infiltrating mononuclear cells in all forms of glomerulonephritis.
Afferent baroreflex dysfunction and age-related orthostatic hypotension
Authors: Tonkin A. L. , Wing L. M. H. , Morris M. J. , Kapoor V. 
Published: August 2015

1. To test the hypothesis that in apparently healthy elderly subjects with orthostatic hypotension there is afferent baroreflex dysfunction, cardiovascular and neurohumoral responses were measured after separate stimuli which activated baroreceptor (head-up tilt) and non-baroreceptor (cold stress, isometric exercise) afferent pathways.
2. In 15 healthy elderly control subjects blood pressure did not change with 60° head-up tilting and there was a moderate increase in heart rate, whereas in 13 subjects with age-related orthostatic hypotension head-up tilting was associated with a marked fall in blood pressure but a similar heart rate response to that in the elderly control group. In contrast, both groups of subjects had similar blood pressure and heart rate responses to cold stress and sustained isometric exercise.
3. Nine subjects with autonomic neuropathy also showed a marked hypotensive response to head-up tilt, but produced no pressor response to cold stress or isometric exercise.
4. The plasma concentrations of noradrenaline, adrenaline and neuropeptide-Y-like immunoreactivity rose and that of atrial natriuretic peptide fell after head-up tilt in the study population as a whole. There were no significant differences between groups despite the much greater blood pressure drops in the subjects with autonomic neuropathy and in those with age-associated orthostatic hypotension.
5. The aorto-iliac pulse wave velocity index was significantly higher in subjects with age-associated orthostatic hypotension compared with that in control subjects.
6. The pattern of responses to the separate stresses observed in the group with age-associated orthostatic hypotension is characteristic and different from that in the elderly control subjects and the subjects with autonomic neuropathy. It suggests that age-associated orthostatic hypotension is related predominantly to dysfunction in the afferent limb of the baroreflex arc, possibly partially caused by a splinting of arterial baroreceptors by non-compliant arterial walls.
Measurement of protein synthesis in human skeletal muscle: further investigation of the flooding technique
Authors: McNurlan M. A. , Essen P. , Heys S. D. , Buchan V. , Garlick P. J. , Wernerman J. 
Published: August 2015

1. The rate of protein synthesis in quadriceps muscle of healthy subjects estimated from the incorporation of l-[1-13C]leucine given by continuous infusion was 1.1%/day. The estimate of protein synthesis from the incorporation of a flooding amount of labelled leucine was 1.8%/day (sd 0.65). The possibility that the higher rate obtained with the flooding technique arose from stimulation of protein synthesis by the large amount of leucine is unlikely.
2. The same rate of protein synthesis (1.7%/day, sd 0.3) was obtained with a flooding amount (0.05 g/kg) of a different amino acid, l-[1-13C]phenylalanine, as was obtained with leucine.
3. Incorporation of l-[1-13C]phenylalanine was not affected by simultaneous injection of leucine (1.7%/day, sd 0.7) or valine (1.6%/day, sd 0.4).
4. Protein synthesis, assessed in a completely different way from the proportion of polyribosomes isolated from the skeletal muscle, was unaltered by the injection of 0.05 g of l-leucine/kg (44.6%, sd 8.5 versus 43.8%, sd 7.7).
5. Good agreement in estimates of protein synthesis was observed in subjects in whom both legs were measured with both l-[1-13C]leucine (mean difference 0.16%/day) and l-[1-13C]phenylalanine (mean difference 0.2%/day).
Anti-aggregatory effects of physiological concentrations of adenosine in human whole blood as assessed by filtragometry
Authors: Söderbäck U. , Sollevi A. , Wallen N. H. , Larsson P. T. , Hjemdahl P. 
Published: August 2015

1. The anti-aggregatory effect of adenosine (0.3–10 μmol/l), alone or in combination with the adenosine-uptake inhibitor dipyridamole (2 μmol/l), was studied in vitro in whole blood from 11 healthy subjects by filtragometry.
2. ADP (0.05–0.1 μmol/l) was used to reduce the filter occlusion time (tA, a measure of platelet aggregate formation in blood) from approximately 600 s to 71–101 s in the absence of other agents.
3. Adenosine was infused into the tubing system of the filtragometer, yielding a contact time of &gt;25 s with the blood before the filter. Adenosine did not influence the aggregatory response to ADP significantly at 0.3 μmol/l in plasma, whereas tA was prolonged by 19 ± 6% (P &lt;0.02) at 1 μmol/l adenosine and by 259 ± 78% (P &lt;0.02) at 3 μmol/l adenosine.
4. When the rapid elimination of adenosine from plasma was prevented by 2 μmol/l dipyridamole, adenosine caused marked prolongation of ADP-induced tA, with significant effects at 0.3 μmol/l (± 143 ± 72%, P &lt;0.05). Dipyridamole per se did not affect tA values.
5. The present results suggest that adenosine has a transient anti-aggregatory effect in whole blood at about 0.3 μmol/l, as this is the highest possible calculated concentration of adenosine at the filter of the apparatus when 1 μmol/l adenosine is infused in the absence of dipyridamole or when 0.3 μmol/l adenosine is infused in its presence.
6. It is concluded that adenosine has anti-aggregatory effects at submicromolar (physiological) concentrations in human whole blood. The effect of adenosine seems to be transient, indicating a role for adenosine as a localized platelet-stabilizing factor in the vicinity of, for example, the endothelium.
Serum creatine kinase MM isoforms in hypertrophic cardiomyopathy
Authors: Hamada Mareomi , Ohtani Takashi , Sekiya Michihito , Fujiwara Yasushi , Sumimoto Takumi , Hiwada Kunio , Morita Shigeki , Tsukada Hiroshi 
Published: August 2015

1. To determine whether a persistent release of creatine kinase from the myocardium occurs in patients with hypertrophic cardiomyopathy, the activities of serum creatine kinase MM isoforms were measured in 22 patients with hypertrophic cardiomyopathy and in 14 normal control subjects.
2. Serum creatine kinase MB activity was significantly higher in patients with hypertrophic cardiomyopathy (7.8 ± 3.8 i.u./l) than in normal control subjects (0.4 ± 0.8 i.u./l; P &lt; 0.01).
3. Serum MMa, MMb and MMc activities in patients with hypertrophic cardiomyopathy were 19.4 ± 4.1%, 26.7 ± 2.5% and 33.5 ± 7.0% of the total creatine kinase MM activity, respectively. These values for each isoform were significantly different from those in normal control subjects (11.3 ± 3.0%, 21.5 ± 4.4% and 40.7 ± 7.0%, respectively). The MMa/MMc activity ratio was significantly higher in patients with hypertrophic cardiomyopathy (0.61 ± 0.25) than in normal control subjects (0.30 ± 0.10; P &lt; 0.01).
4. Our results indicate that a small amount of the myocardial tissue isoform of creatine kinase MM (MMa) is constantly released in many patients with hypertrophic cardiomyopathy.
Effect of varying alveolar oxygen partial pressure on diffusing capacity for nitric oxide and carbon monoxide, membrane diffusing capacity and lung capillary blood volume
Authors: Borland C. D. R. , Cox Y. 
Published: August 2015

1. To examine the effect of varying oxygen partial pressure (Pao2) on nitric oxide (DLNO) and carbon monoxide (DLCO) diffusing capacity (transfer factor), 10 subjects performed combined DLCO/DLNO measurements with the inspired mixture made up with three different oxygen concentrations (25%, 18% and 15%) to give Pao2 values of 12–20 kPa.
2. A novel method is described for calculating membrane diffusing capacity (DM) and pulmonary capillary volume (Qc) from DLNO and DLCO.
3. The mean DMCO was 52.89 mmol min−1 kPa−1 and Qc was 0.056 litre. Reducing Pao2 from 20 to 12 kPa resulted in an increase in DLCO = −0.124 (O2%) + 11.67 (P &lt; 0.001) and a fall in DLNO = 0.538 (O2%) + 32.01 (P &lt; 0.001) and a fall in DLNO/DLCO = 0.107 (O2%) + 2.52 (P &lt; 0.001). DM (P = 0.59) and Qc (P = 0.64) also tended to fall with falling Pao2.
4. It appears more likely that the minor reduction in DLNO that we have observed with falling Pao2 is due to diffusion rather than reaction limitation.
Islet amyloid polypeptide: production by an osteoblast cell line and possible role as a paracrine regulator of osteoclast function in man
Authors: Gilbey Stephen G. , Ghatei Mohammad A. , Bretherton-Watt Deborah , Zaidi Mone , Jones Phillip M. , Perera Tim , Beacham Jeremy , Girgis Samia , Bloom Stephen R. 
Published: August 2015

1. The recently discovered peptide islet amyloid polypeptide shows considerable sequence homology with calcitonin-gene-related peptide, itself an alternative product of the calcitonin gene. The possibility that islet amyloid polypeptide might affect calcium homoeostasis and bone cell function was investigated.
2. Islet amyloid polypeptide messenger RNA was found to be expressed by human HTb 96 osteoblast-like cells in culture, and islet amyloid polypeptide immunoreactivity was present in the cell culture medium.
3. Infusion of islet amyloid polypeptide (150 pmol min−1 kg−1) caused a fall in serum calcium and phosphate concentrations in five patients with Paget's disease of the bone. This was similar to that caused by infusion of calcitonin (50 pmol min−1 kg−1).
4. These findings raise the possibility that islet amyloid polypeptide may act as a local factor within bone, produced by osteoblasts and regulating osteoclast function. The possibility of an action of islet amyloid polypeptide on the renal handling of calcium seems unlikely but is not totally excluded.