bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Treatment with Calcium Antagonists in Vitro and in Vivo on the Contractile Response of Isolated Rat and Human Detrusor Muscle
Authors: Elliott Ruth A. , Norman Robert I. , Parker Stuart G. , Whitaker R. Paul , Castleden C. Mark
Published: August 2015

1. The effect of calcium antagonists on the contractile response of human and rat isolated detrusor muscle in vitro was investigated. The effect of treatment with nimodipine on rat detrusor muscle in vivo was also examined.

2. Nimodipine 0.1 μmol/l, nifedipine 0.1 μmol/l, nifedipine 0.25 μmol/l and verapamil 1.5 μmol/l reduced the maximum contractile response of isolated human detrusor muscle to carbachol by 42%, 35%, 41% and 28% respectively (P < 0.01). Verapamil 0.1 μmol/l had no significant effect on contractile response.

3. Nimodipine 0.1 μmol/l reduced the maximum contractile response of isolated rat detrusor muscle in vitro to electrical field stimulation and carbachol by 53% and 84% respectively (P < 0.01).

4. Rats were pretreated with nimodipine for 8 days (5 mg day−1 kg−1) or with a single dose. Serum nimodipine concentrations were higher in rats treated for 8 days. In rats treated with nimodipine for 8 days there was no significant difference in detrusor contractile response compared with controls. However, after one dose of nimodipine the maximum contractile response was significantly reduced compared with controls (P < 0.05).

5. At the concentrations studied, nimodipine had a greater inhibitory effect on the contractile response of isolated human detrusor muscle. Nimodipine significantly reduced the contractile response of rat detrusor muscle in vitro and after a single dose in vivo, but had no significant effect after 8 days' treatment in vivo. It is possible that chronic oral treatment with nimodipine caused an up-regulation of 1,4-dihydropyridine-sensitive calcium channels, which may explain the lack of clinical effect of chronic treatment with calcium antagonists in patients with detrusor instability.
Renal Effects of Amino Acids and Dopamine in Renal Transplant Recipients Treated with or without Cyclosporin A
Authors: Hansen Jesper Melchior , Olsen Niels Vidiendal , Leyssac Paul Peter
Published: August 2015

1. The nephrotoxic effects of cyclosporin A may diminish the ability of the transplanted kidney to increase the glomerular filtration rate and effective renal plasma flow during infusion of dopamine or amino acids.

2. The present study included 16 renal transplant recipients transplanted for more than 6 months. Eight of the patients were on immunosuppressive treatment including cyclosporin A [cyclosporin A group; cyclosporin A dose, 2.7 ± 0.4 mg/kg; S-creatinine, 105 ± 12 μmol/l (means ± SEM)], whereas eight patients had never received cyclosporin A (non-cyclosporin A group; S-creatinine, 89 ± 6 μmol/l). The renal response to infusion of dopamine and of amino acids was investigated on two separate days. All clearance measurements were carried out at nadir cyclosporin A blood levels.

3. Effective renal plasma flow increased significantly in the non-cyclosporin A group and cyclosporin A group by 31.0 ± 4.1% and 35.9 ± 6.6%, respectively, during infusion of dopamine, and by 18.7 ± 6.7% and 13.9 ± 5.3%, respectively, during infusion of amino acids. Glomerular filtration rate increased significantly in the non-cyclosporin A group and cyclosporin A group by 15.7 ± 3.3% and 18.3 ± 4.7%, respectively, during infusion of dopamine, and by 18.9 ± 4.5% and 15.0 ± 3.7%, respectively, during infusion of amino acids.

4. Furthermore, the amino acid- and dopamine-induced increases in proximal tubular outflow (renal clearance of lithium) and calculated changes in renal proximal and distal tubular handling of sodium (and water) were comparable between the two groups of patients. Dopamine caused significant natriuresis in both groups.

5. In conclusion, low-dose cyclosporin A seems not to attenuate the renal haemodynamic and tubular response to infusions of amino acids and of dopamine in renal transplant recipients with a good graft function.
Comparison of the Mitogenic Activity of Human Epidermal Growth Factor 1-53 and Epidermal Growth Factor 1-48 in Vitro and in Vivo
Authors: Goodlad R. A. , Boulton R. , Playford R. J.
Published: August 2015

1. Epidermal growth factor is secreted into the gut lumen as a 53 amino acid peptide in vivo. Several preliminary studies have examined the clinical benefit of recombinant epidermal growth factor in intestinal disease, but there is inconsistency in the form of epidermal growth factor used (some using epidermal growth factor 1–48 and some epidermal growth factor 1–53), making comparisons difficult to evaluate.

2. We therefore examined the relative potency of recombinant epidermal growth factor 1–48 and epidermal growth factor 1–53 in stimulating [3H]thymidine uptake into primary rat hepatocytes at various doses in vitro and on various parameters of proliferation within the gastrointestinal tract when infused intravenously at 50 nmol day−1 kg−1 into rats receiving total parenteral nutrition.

3. Epidermal growth factor 1–53 was about twice as potent as epidermal growth factor 1–48 in its ability to stimulate [3H]thymidine incorporation into rat hepatocytes in vitro. In vivo studies supported this finding as, in both the small and large intestine, epidermal growth factor 1–53 caused about a 30% greater stimulation of intestinal growth than epidermal growth factor 1–48 (P < 0.001).

4. The 1–48 truncated form of epidermal growth factor is less active than the full-length molecule in vitro and in vivo. This must be borne in mind when comparing clinical trials that use different forms of recombinant epidermal growth factor.
Skin Microcirculation of the Foot in Diabetic Neuropathy
Authors: Netten Paetrick M. , Wollersheim Hub , Thien Theo , Lutterman Jos A.
Published: August 2015

1. In the feet of patients with diabetic neuropathy, total skin blood flow is increased due to an increased shunt flow. The question is, does this increased anastomotic shunt flow lead to either under- or overperfused nutritive capillaries.

2. To solve this question, skin microcirculation tests of the left big toe were performed in 20 healthy control subjects and in 40 insulin-dependent diabetic patients without macroangiopathy, 20 without and 20 with neuropathy. Skin temperature measurements and laser Doppler fluxmetry were performed to record mainly shunt flow and capillaroscopy to study nailfold capillary blood flow.

3. The insulin-dependent diabetic patients with neuropathy had a higher baseline skin temperature (mean ± SEM; 30.0 ± 0.6°C) and laser Doppler fluxmetry [26.2 ± 2.2 perfusion units (pu)] than patients without neuropathy (27.2 ± 0.8°C, P < 0.01; 16.1 ± 2.0 pu, P < 0.01) and healthy control subjects (27.9 ± 0.7°C, P < 0.05; 18.6 ± 2.8 pu, P < 0.05). Sympathetic stimulation (inspiratory gasp) resulted in a smaller laser Doppler fluxmetry decrease in the neuropathic patients (31.4 ± 4.6%) compared with non-neuropathic patients (48.2 ± 5.1%, P < 0.05) and control subjects (49.0 ± 3.8%, P < 0.05), while no difference between the three groups was seen in the laser Doppler fluxmetry decrease during a postural vasoconstriction test. The number of visible capillaries was highest in the neuropathic patients (10.2 ± 0.6/0.5 mm2), when compared with non-neuropathic patients (8.7 ± 1.2/0.5 mm2, P < 0.05) and control subjects (8.3 ± 0.3/0.5 mm2, P < 0.001). Capillary blood-cell velocity was significantly higher in the neuropathic patients (0.32 ± 0.05 mm/s) compared with non-neuropathic patients (0.23 ± 0.03 mm/s, P < 0.05) and control subjects (0.23 ± 0.02 mm/s, P < 0.01).

4. We conclude that there is an overperfused nutritive capillary circulation in the feet of patients with diabetic neuropathy. This is in contradiction to the capillary steal phenomenon and favours the hyperdynamic hypothesis to explain the decreased healing potential in diabetic neuropathic foot ulceration.
Effects of Hormone Replacement Therapy on Muscle Performance and Balance in Post-Menopausal Women
Authors: Armstrong Alison L. , Oborne Janet , Coupland Carol A. C. , MacPherson Marion B. , Bassey E. Joan , Wallace W. Angus
Published: August 2015

1. A randomized controlled trial of the effect of oral hormone replacement therapy plus calcium compared with calcium alone on balance, muscle performance and falls was conducted over 48 weeks in 116 post-menopausal women (aged 45–70 years), all of whom had suffered a distal radial fracture during the previous 3 months. Treatment was with Prempak C or Premarin 0.625 mg in the test group with 1 g calcium daily (Sandocal) in both groups. Measurements were made of balance, assessed as sway, leg extensor power and self-paced walking speed, at 12-week intervals over 24 weeks. Hand grip strength was measured every 12 weeks for 48 weeks, and falls in the preceding 12 weeks were recorded at each visit.

2. There was no relation between initial levels of oestradiol and any other variable assessed, except body mass. Levels of follicle-stimulating hormone in the test group were in the premenopausal range. There was no significant change attributable to hormone replacement therapy at any time point in any of the outcome variables. The only significant difference was an increase of 4.2% (95% confidence interval 0.7–7.6%) in leg extensor power in the control group (calcium alone) compared with the group treated with hormone replacement therapy.

3. Of the total group, 37% fell again during the year, with three patients suffering a further fracture. Frequent fallers swayed significantly more often than the others, but there was no evidence that their muscle strength was poorer or that the group treated with hormone replacement therapy fell less frequently.

4. Hormone replacement therapy did not increase muscle performance, improve balance or reduce falls over a year in middle-aged women.
Association of Antral Mucosal Levels of Interleukin 8 and Reactive Oxygen Radicals in Patients Infected with Helicobacter Pylori
Authors: Zhang Q. B. , Dawodu J. B. , Husain A. , Etolhi G. , Gemmell C. G. , Russell R. I.
Published: August 2015

1. Helicobacter pylori infection is characterized by an infiltration of neutrophils in the gastric mucosa. Neutrophil activation is an important source of reactive oxygen radicals, which cause tissue damage. Studies have shown that in Helicobacter pylori-infected patients there is increased mucosal production of interleukin 8. However, the role of interleukin 8 in the Helicobacter pylori-related inflammatory process and its relationship with reactive oxygen radicals remains to be clarified. The aims of this study were to investigate if there is any association between antral mucosal levels of interleukin 8 and reactive oxygen radicals and their relationship to gastric antral inflammation.

2. Fifty-two patients referred for endoscopy were recruited into the study. Gastric antral biopsies were taken for histology, culture and measurement of interleukin 8 and chemiluminescence (measuring reactive oxygen radicals). Interleukin 8 was measured by ELISA and the result expressed as pg/mg biopsy. Luminol-enhanced chemiluminescence was measured as mV min−1 mg−1 biopsy. Antral inflammation was assessed by a pathologist in a blinded fashion.

3. Antral mucosal levels of interleukin 8 and reactive oxygen radicals were significantly higher in Helicobacter pylori-colonized mucosa than in Helicobacter pylori-negative mucosa. After the eradication of Helicobacter pylori in patients with duodenal ulcer the median values (ranges) of interleukin 8 and reactive oxygen radicals fell from 1.21 (0.10-2.40) to 0.65 (0.00-1.60) and from 110.0 (10.0-959.0) to 14.5 (0.0-85.0) respectively. There was a positive correlation between interleukin 8 concentration and chemiluminescence response in the antral mucosa (r = 0.72). A higher interleukin 8 concentration was associated with greater neutrophil infiltration (r = 0.72) and mononuclear cell infiltration (r = 0.55); the magnitude of the chemiluminescence response was also positively associated with neutrophil (r = 0.77) and mononuclear cell infiltration (r = 0.59).

4. Interleukin 8 concentration is associated with an infiltration of neutrophils and mononuclear cells and is correlated with the production of reactive oxygen radicals in antral gastric mucosa infected with Helicobacter pylori. These findings suggest that interleukin 8 may be important in attracting and activating phagocytes to release reactive oxygen radicals, thereby causing mucosal damage.
Endothelial Function in Subcutaneous Resistance Arteries from Elderly Hypertensive and Normotensive Subjects
Authors: James Martin A. , Watt Pamela A. C. , Potter John F. , Thurston Herbert , Swales John D.
Published: August 2015

1. Previous studies have indicated that younger hypertensive subjects may have abnormal endothelium-dependent relaxation, which could contribute to the elevated peripheral resistance seen in established hypertension. This study was designed to examine the functional behaviour of the endothelium of small arteries from elderly hypertensive and normotensive subjects.

2. Resistance arteries were obtained from gluteal biopsies taken under local anaesthesia in 28 subjects of mean age 70 (range 60–76) years, and studied in an isometric myograph. Eighteen subjects had untreated essential hypertension, and 10 were normotensive.

3. After measurement of the contractile response to noradrenaline, relaxation responses to a variety of endothelium-dependent (acetylcholine and bradykinin) and endothelium-independent (iloprost and sodium nitroprusside) mechanisms were assessed in vessels precontracted with noradrenaline. Endothelium-dependent responses were also studied after incubation with NG-nitro-l-arginine to inhibit nitric oxide synthase.

4. There were no significant differences in the contraction or relaxation responses between elderly subjects with or without high blood pressure. Inhibition of nitric oxide synthase prevented any relaxation with acetylcholine and significantly attenuated the relaxation with bradykinin. Near-complete relaxation was however achieved with the endothelium-independent vasodilator sodium nitroprusside.

5. Hypertension in elderly subjects is not associated with a reduction in endothelial vasodilating function in the subcutaneous vessels of the gluteal region compared with age-matched normotensive controls. The results of this study do not support the hypothesis of a defect of resistance artery endothelium-dependent relaxation in the pathophysiology of hypertension in the elderly.
Phagocytic Degradation of Chylomicron Remnants by Fibroblasts from Subjects with Homozygous Familial Hypercholesterolemia
Authors: Yu Kenneth C.-W. , Smith Darrin , Yamamoto Akira , Kawaguchi Akito , Harada-Shiba Mariko , Yamamura Taku , Mamo John C. L.
Published: August 2015

1. Familial hypercholesterolaemia is a common genetic abnormality in man characterized by premature atherogenesis as a consequence of disturbed lipoprotein metabolism. Chylomicrons, which represent intestinally derived lipoproteins, are cleared poorly in familial hypercholesterolaemia which may explain the increased retention of chylomicron remnants in arterial fatty lesions. However, cellular uptake of chylomicron remnants in familial hypercholesterolaemia remains unclear. This study determined the quantitative significance of non-low-density lipoprotein receptor-mediated uptake in fibroblasts from subjects with homozygous familial hypercholesterolaemia.

2. The metabolism of chylomicron remnants was assessed in fibroblasts from subjects with homozygous familial hypercholesterolaemia who lack low-density lipoprotein receptors. Compared with fibroblasts from normolipidaemic subjects, binding and degradation of chylomicron remnants was reduced by about two-thirds. Nevertheless, degradation of chylomicron remnants in cells from subjects with familial hypercholesterolaemia persisted in the absence of functioning low-density lipoprotein receptors.

3. Binding of chylomicron remnants to fibroblasts from subjects with familial hypercholesterolaemia was saturable. Unlabelled chylomicron remnants competed efficiently for binding but unlabelled low-density lipoprotein or a monoclonal antibody specific to the human low-density lipoprotein receptor had little effect on binding or degradation.

4. Polyinosinic acid did not alter binding and degradation of chylomicron remnants by fibroblasts from subjects with familial hypercholesterolaemia, ruling out involvement of the scavenger receptor. Lactoferrin was found to inhibit binding and degradation of chylomicron remnants by fibroblasts from subjects with familial hypercholesterolaemia by approximately 50%, implicating involvement of the α2-macroglobulin receptor.

5. Cytochalasin D blocked degradation of chylomicron remnants at 37°C in fibroblasts from subjects with familial hypercholesterolaemia by more than 80% but had no effect on binding at 4°C, consistent with a phagocytic uptake pathway. Collectively, the data suggest that chylomicron remnants bind to a cell-surface protein which initiates phagocytosis and that lactoferrin interferes with binding to this putative cell-surface protein. Phagocytic uptake of chylomicron remnants provides an additional mechanism whereby cells from subjects with familial hypercholesterolaemia can accumulate lipid.
Effect of two Forms of Granulocyte-Colony-Stimulating Factor on Hepatic Regeneration after 70% Partial Hepatectomy in Rats
Authors: Theocharis Stamatios E. , Agapitos Emmanuel B. , Margeli Alexandra P. , Goutas Nicolaos D. , Kittas Christos N. , Davaris Panayiotis S.
Published: August 2015

1. The purpose of this study was to determine whether the commercially available forms of granulocyte-colony-stimulating factor exert the same beneficial effect on hepatic regeneration after 70% partial hepatectomy in rats. Adult male Wistar rats received either the two commercially available forms of granulocyte-colony-stimulating factor (Filgrastim or Lenograstim), or saline, simultaneously with partial hepatectomy. Hepatic regeneration was documented by determining [3H] thymidine incorporation into hepatic DNA, liver thymidine kinase activity, mitotic index and proliferating cell nuclear antigen immunostaining, at various time points after partial hepatectomy.

2. DNA biosynthesis, liver thymidine kinase activity and mitotic index of hepatocytes were not only enhanced (P < 0.001) in rats that received 150 μg of Filgrastim or Lenograstim/kg of body weight, but occurred earlier than in saline-treated partially hepatectomized rats. The administration of both forms of granulocyte-colony-stimulating factor, at the dose of 15 μg/kg of body weight, did not affect liver proliferative capacity, compared with observations in simply partially hepatectomized rats. High mitotic and proliferating cell nuclear antigen indices appeared earlier than those estimated in simply partially hepatectomized rats, when 150 μg of Filgrastim or Lenograstim/kg of body weight were administered.

3. These findings suggest that both pharmacologically available forms of granulocyte-colony-stimulating factor at a dose of 150 μg/kg of body weight are able to augment liver regenerative capacity, to the same extent, in this animal model of controlled hepatie proliferation.
Tissue Expression of Components of the Renin—Angiotensin System in Experimental Post-Infarction Heart Failure in Rats: Effects of Heart Failure and Angiotensin-Converting Enzyme Inhibitor Treatment
Authors: Kelly Martin P. , Kahr OLE , Aalkjaer Christian , Cumin Frederic , Samani Nilesh J
Published: August 2015

1. It has been suggested that local tissue renin—angiotensin systems may be activated in heart failure and that effects on such systems may, at least partially, explain the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in this syndrome. To investigate these hypotheses, we examined expression of renin-angiotensin system components in several tissues in a rodent model of post-myocardial infarction (MI) heart failure, and analysed whether such expression is modified by ACE inhibitor treatment.

2. Four groups of rats (n = 8–12 per group) were studied 30 days after surgery: (A) sham-operated rats with no treatment, (B) rats with post-MI heart failure induced by ligation of the left coronary artery, (C) sham-operated rats treated with the ACE inhibitor perindopril (1.5 mg day−1 kg−1), and (D) rats as per B, but treated with perindopril. Expression of renin, angiotensinogen, ACE and angiotensin subtype 1 receptor was assessed by quantification of their respective mRNAs by Northern blotting.

3. Renal renin mRNA increased 2-fold in animals with MI (group B) compared with controls (group A) (P < 0.05) and between 50 and 100-fold after ACE inhibitor treatment (P < 0.001). No change in renin gene expression was found in any extra-renal site either following MI or after ACE inhibitor treatment. Hepatic angiotensinogen mRNA level was similar in all groups, but kidney angiotensinogen mRNA level was increased 1.6-fold (P < 0.01) in the groups receiving perindopril. ACE mRNA level in the lung was not affected by ACE inhibitor treatment but decreased by 50% following MI (groups B and D, P < 0.01). This was associated with a similar (50%, P < 0.01) fall in lung ACE activity and was correlated with the severity of heart failure. Angiotensin subtype 1 receptor mRNA level was not affected in any tissue by either MI or ACE inhibitor treatment.

4. We did not find a systematic activation of tissue renin-angiotensin systems, as assessed by steady-state mRNA levels of key components of the system in experimental post-MI heart failure, or a major effect of ACE inhibitor treatment on expression of these components. However, we observed tissue-specific changes in expression of selected components of the renin-angiotensin system in the kidney and the lung in post-MI heart failure and after ACE inhibitor treatment, which may be of relevance to the pathophysiology of the syndrome and the effects of ACE inhibition.
Female sex Hormones do not Influence Arterial wall Properties during the Normal Menstrual Cycle
Authors: Willekes Christine , Hoogland Henk J. , Keizer Hans A. , Hoeks Arnold P. , Reneman Robert S.
Published: August 2015

1. In previous studies, the elastic properties of the common carotid artery were found to differ between men and women. In these studies, however, the phase of the menstrual cycle was not taken into consideration. It was the aim of the present study to investigate the effect of changing ovarian hormone levels during the normal menstrual cycle on the arterial wall properties of female large arteries.

2. We investigated the elastic right common carotid artery and the muscular right common femoral artery of normotensive young (18–35 years) female subjects (n = 12). The arterial distensibility and cross-sectional compliance coefficients were determined by the use of a specially designed ultrasonic wall-tracking device and measurements of automatic brachial artery cuff blood pressure. The phase of the menstrual cycle was assessed by ultrasonographic evaluation and measurement of 17β-oestradiol and progesterone blood plasma levels.

3. The distensibility coefficient and the cross-sectional compliance coefficient of both the common carotid and the common femoral artery did not change significantly during the normal menstrual cycle despite evidently changing ovarian hormone levels.

4. We conclude that the menstrual cycle does not influence the arterial wall properties of either the elastic common carotid artery or the muscular common femoral artery.
Microdialysis of Human Breast Tissue during the Menstrual Cycle
Authors: Dabrosin Charlotta , Hallström Åse , Ungerstedt Urban , Hammar Mats
Published: August 2015

1. Previously it has been impossible to perform studies of human breast tissue in vivo. In this study, we investigated whether the microdialysis technique is applicable in human breast tissue and whether the concentrations of amino acids, lactate and pyruvate change during the menstrual cycle.

2. Microdialysis was performed twice during the menstrual cycle in eight healthy women, in the breast and subcutaneous fat. Amino acids, lactate and pyruvate were analysed by HPLC.

3. None of the women showed any complications, such as bleeding or infection, after the experiments. The concentrations of aspartic acid, asparagine, serine, glycine, threonine, tyrosine and ornithine were decreased in the breast late in the menstrual cycle. In the subcutaneous fat, the concentration of glycine decreased late in the cycle.

4. This study has shown that microdialysis is a safe technique and is suitable for investigations of human breast tissue. Our data indicate that metabolism in the breast changes during the menstrual cycle. The lower levels of specific amino acids late in the menstrual cycle could indicate a higher proliferative and/or apoptotic activity during this period. However, the data we have obtained cannot yet be fully explained.
Compound Heterozygote for Both Rare Apolipoprotein E1(Gly127→Asp, Arg158→Cys) and E3(Cys112 → Arg, Arg251 → Gly) Alleles in a Multigeneration Pedigree with Hyperlipoproteinaemia
Authors: Richard Pascale , Beucler Isabelle , De Zulueta Maria Pascual , Biteau Nicolas , De Gennes Jean-Luc , Iron Albert
Published: August 2015

1. A French multigeneration pedigree with hyperlipoproteinaemia was investigated for the transmission of the rare apolipoprotein E1(Gly127 → Asp, Arg158 → Cys) variant. The proband, a 46-year-old male carrying the rare apoE1 variant, presented a severe type III hyperlipoproteinaemia like his three brothers and his sister.

2. ApoE phenotyping and genotyping showed a discrepancy in the second allele carried by the proband's wife and two of her children, thus suggesting another apoE gene mutation. Cloning and sequencing of the entire exon 4 demonstrated a point mutation at codon 251, leading to an apoE3(Cys112 → Arg, Arg251 → Gly) allele. The proband's wife was normolipaemic and heterozygous for this rare isoform and the common apoE3 protein. The rare apoE3(Cys112 → Arg, Arg251 → Gly) allele has been transmitted to her two daughters. The first, aged 19, was normolipaemic and heterozygous for this allele and the common apoE2 allele. The second, carrying both the rare isoforms apoE1(Gly127 → Asp, Arg158 → Cys) and apoE3(Cys112 → Arg, Arg251 → Gly), presented a hypertriglyceridaemia at the age of 10.

3. The exploration of apoE status associated with plasma lipid levels and lipoprotein profiles in this three-generation pedigree made it possible to describe a compound heterozygote for two mutated alleles, one mutation being located in the N-terminal domain of the apoE protein and the other arising in the C-terminal domain.
Cough Frequency and Cough-Receptor Sensitivity are Increased in Man at Altitude
Authors: Barry P.W. , Mason N.P. , Riordan M. , O'Callaghan C.
Published: August 2015

1. Travellers to high altitude often complain of paroxysmal cough, which has not been previously investigated. We recorded overnight cough frequency and cough-receptor sensitivity to inhaled citric acid in a group of climbers travelling to 5300 m or higher.

2. Cough frequency, monitored in ten subjects, increased from a median of 0 coughs at sea level (range 0–1) to 5 coughs at 5000 m (range 0–13) and to over 60 coughs in subjects ascending to 7000 m. Citric acid cough threshold, measured in 42 subjects, was unchanged on arrival at 5300 m compared with sea level (geometric mean difference 1.26, 95% confidence intervals 0.84–1.89, P = 0.25), but was significantly reduced after 6 days, or more, at altitude compared with sea level (geometric mean difference 2.2, 95% confidence intervals 1.54–3.15, P = 0.0002). Cough threshold was not related to symptoms of acute mountain sickness, oxygen saturation, carbon dioxide tension or lung function.

3. These results indicate an increase in cough and cough-receptor sensitivity after some days at altitude. This may be due to respiratory tract damage from breathing cold dry air at increased ventilatory rates. Other explanations, such as sub-clinical pulmonary oedema or an effect on the cough centre of acclimatization to altitude, cannot be excluded.
Variability of Near-Fainting Responses in Healthy 6–16-Year-old Subjects
Authors: Catherine C.E. , van Steenwijk de Jong-de Vos , Wieling Wouter , Harms Mark P. M. , Wesseling Karel H.
Published: August 2015

1. Fainting is a common phenomenon in young subjects, but the final events before the actual faint are not well known. The aim of the present study was to study the inter-individual variability of haemodynamic events associated with near-fainting in children and teenagers.

2. Sixty-eight healthy subjects (aged 6–16 years) performed a 70° tilt-up test with intravascular instrumentation for 5 min. Responses in 29 near-fainting subjects were analysed and compared with 39 non-fainting subjects. Arterial pressure was measured by Finapres. Left ventricular stroke volume was computed from the pressure pulsation waveform.

3. Inability to maintain vasomotor tone was the mechanism underlying near-fainting in the vast majority of near-fainting subjects. The three classical haemodynamic responses (vasovagal, vasodepressor and vagal) could be recognized, but large individual differences were found. After tilt back, blood pressure in near-fainters showed a mirror response to the stage before tilt-back; blood pressure gradually increased and was normal at 1 min after tilt-back.

4. The variability in haemodynamic responses on approach of an orthostatic faint is wide in the young.
Hyperdynamic Circulation of Cirrhotic Rats with Ascites: Role of Endotoxin, Tumour Necrosis Factor-α and Nitric Oxide
Authors: Chu Chi-Jen , Lee Fa-Yauh , Wang Sun-Sang , Rei-Hwa LU , Tsai Yang-Te , Lin Han-Chieh , Hou Ming-Chih , Chan Che-Chang , Lee Shou-Dong
Published: August 2015

1. Hyperdynamic circulation observed in portal hypertensive states is characterized by generalized vasodilatation, increased cardiac index and increased systemic and regional blood flows. Endotoxin, tumour necrosis factor-alpha (TNF-α) and nitric oxide (NO) have been reported to be involved in the pathogenesis of hyperdynamic circulation, but the interactions between endotoxin, TNF-α and NO in cirrhotic rats with ascites have never been specifically addressed.

2. This study was designed to determine systemic and portal haemodynamics and plasma levels of endotoxin, TNF-α and nitrate/nitrite in cirrhotic rats with ascites and investigate the relationships between these substances.

3. Plasma concentrations of endotoxin, TNF-α and nitrate/nitrite (an index of NO production) were determined in 25 cirrhotic rats with ascites and 17 control rats using the Limulus assay, ELISA and a colorimetric assay respectively. In addition, haemodynamic studies were performed in another ten cirrhotic rats with ascites and ten control rats.

4. Cirrhotic rats with ascites had hyperdynamic circulation accompanied by increased plasma levels of endotoxin, TNF-α and nitrate/nitrite, as compared with control rats. Significant correlation existed between plasma levels of endotoxin and nitrate/nitrite (r = 0.59, P < 0.0001) and between plasma levels of endotoxin and TNF-α (r = 0.63, P < 0.0001). No correlation was detected between plasma levels of TNF-α and nitrate/nitrite (r = 0.24, P > 0.05).

5. This study suggests that endotoxaemia developed in cirrhotic rats with ascites may stimulate NO formation directly or indirectly via cytokine cascade, and consequently participate in the development and/or maintenance of hyperdynamic circulation.
Brown Adipose Tissue and Its Uncoupling Protein in Chronically Hypoxic Rats
Authors: Mortola Jacopo P. , Naso Lina
Published: August 2015

1. Hypoxia is known to decrease thermogenesis. We set out to determine whether this is accompanied by alterations in the brown adipose tissue, which is a major source of non-shivering thermogenesis.

2. Measurements were performed on 25- and 64-day-old rats, after 4 days of hypoxia (10% inspired O2), and on ∼3.5-month-old rats in hypobaric hypoxia since birth, at an ambient temperature of 25°C.

3. All hypoxic rats had higher haematocrit and lower body mass than corresponding controls.

4. In the 25-day-old rats, hypoxia had minimal and non significant effects on brown adipose tissue mass, proteins and DNA concentration. The content of the mitochondrial uncoupling protein thermogenin, evaluated by immunoblot after electrophoretic separation, relative to the cytoskeleton actin (UCP/Act), was not significantly altered.

5. In 25-day-old rats exposed for 4 days to cold (ambient temperature = 7–9°C), brown adipose tissue was hyperplastic, with increased UCP/Act; hypoxia did not appreciably alter the response to cold.

6. In the 2-month-old rats, after 4 days of hypoxia UCP/Act was reduced to about 40% of control.

7. In the 3.5-month-old rats maintained in hypoxia since birth, brown adipose tissue mass was reduced in proportion to body mass, with little effect on total proteins and DNA; UCP/Act was decreased to about 50% of control.

8. We conclude that chronic hypoxia had a minimal effect on brown adipose tissue total proteins and DNA content. However, the uncoupling protein content can be greatly reduced, depending upon age and duration of hypoxia.
Relationship of Serum Leptin to Total and Truncal Body Fat
Authors: Solin Melina S. , Ball Madeleine J. , Robertson Iain , De Silva Andrea , Pasco Julie A. , Kotowicz Mark A. , Nicholson Geoff C. , Collier Greg R.
Published: August 2015

1. In this study we investigated the relationship between serum leptin levels and body fat distribution in a random sample of women of widely ranging age and body mass index. Anthropometry and dual energy X-ray absorptiometry were used to measure body fat and its distribution.

2. Leptin levels (log transformed) were not significantly correlated with age, but were significantly positively correlated (P < 0.001) with most anthropometric measures except waist-to-hip circumference ratio. The strongest correlations were with total grams of body fat and percentage body fat (r = 0.68 and 0.76 respectively, P < 0.001). When corrected for percentage body fat the partial correlation coefficients for all other measures became non-significant. The correlation with truncal body fat fell significantly from 0.66 to −0.05 after correction, but the partial correlation with total body fat remained significant (P < 0.005) when grams of truncal fat were controlled for (r = 0.21).

3. These results indicate that the relationship of serum leptin to percentage body fat is the strongest, and that truncal body fat, although the most metabolically active, does not appear to have an independent association with serum leptin.
Lipolysis and Lactate Production in Human Skeletal Muscle and Adipose Tissue following Glucose Ingestion
Authors: Kerckhoffs Daniëlle A. J. M. , Arner Peter , Bolinder Jan
Published: August 2015

1. Using microdialysis, we compared lipolysis, as well as the production of lactate, in human adipose tissue and muscle after the ingestion of carbohydrate.

2. The absolute concentrations of glycerol and lactate were measured in subcutaneous adipose tissue, skeletal muscle and arterialized venous blood in eight normal subjects during basal conditions and 4 h after a 75 g oral glucose load. Nutritive blood flow in muscle and adipose tissue was monitored simultaneously with the microdialysis ethanol clearance technique.

3. At baseline, the concentrations of glycerol in adipose tissue and in muscle were about 7 times and about 2.5 times higher respectively than those in plasma. After glucose ingestion, the changes in glycerol concentrations differed significantly between the three compartments (P < 0.0001). In plasma and adipose tissue, the concentrations decreased rapidly and markedly, but returned to baseline levels after 4 h. In muscle, the decrease in glycerol was less pronounced and more protracted.

4. At baseline, the concentrations of lactate in muscle and in adipose tissue were about 3 times and about 1.5 times higher respectively than those in plasma. After the ingestion of glucose, the levels increased transiently in similar ways in muscle, adipose tissue and plasma. The differences in absolute lactate concentrations between the three compartments were maintained after the glucose load (P < 0.001).

5. Adipose tissue blood flow increased transiently after glucose ingestion, whereas muscle blood flow remained unchanged.

6. Both muscle and adipose tissue are a source of glycerol and lactate release during basal conditions and after glucose ingestion. The regulation of lactate production, but not of lipolysis, after carbohydrate ingestion is similar in the two tissues.
Glaxo/MRS Young Investigator Medal: Molecular Studies on Adenosine Deaminase Deficiency and Hereditary Haemorrhagic Telangiectasia
Authors: Shovlin Claire L.
Published: August 2015

1. This manuscript describes two different strategies to progress from the clinical assessment of patients to the identification of disease-causing mutations. In the first disease, recognition of a metabolic abnormality allowed direct molecular analysis of the causal gene. In contrast, localization of the second disease gene by linkage analysis was critical to implicate a gene with a previously unsuspected disease role.

2. Two sisters with chronic respiratory disease and recurrent infections were identified as the first cases of adult onset immunodeficiency due to adenosine deaminase deficiency. Autosomal recessive inheritance of two mutations in the adenosine deaminase gene was demonstrated. Enzyme replacement therapy improved the patients' immunological and clinical status.

3. Individuals with pulmonary arteriovenous malformations were used to identify families with hereditary haemorrhagic telangiectasia (HHT, Rendu-Osler-Weber Syndrome). Linkage studies mapped the HHT disease gene in some families to chromosome 9, and demonstrated genetic heterogeneity. The chromosome 9 disease interval was refined, and several candidate genes were assessed. Following the first description of disease-segregating mutations, a complete analysis of the endoglin gene (which encodes an endothelial cell transforming growth factor-β receptor) identified seven novel mutations. Two mutations did not produce mutant mRNA, and disease severity was comparable between families, indicating that HHT results from stoichiometric insufficiency of endoglin.

4. Each study has implications extending beyond the relatively rare disease analysed. The adenosine-deaminase-deficient patients highlight a treatable cause of HIV-negative CD4+ lymphopenia in adults, perhaps accounting for further cases of ‘non-HIV AIDS’. The HHT studies have illuminated a novel area of vascular pathophysiology, with potential relevance to further disease states.
Influence of Mode of Contraction on the Mechanism of Acetylcholine-Mediated Relaxation of Coronary Arteries from Normotensive and Spontaneously Hypertensive Rats
Authors: Bund Stuart J.
Published: August 2015

1. Endothelium-dependent acetylcholine-mediated relaxations of small coronary arteries (∼200 μm internal diameter) from 20 weeks old spontaneously hypertensive rats (SHR) and normotensive Wistar—Kyoto (WKY) controls were compared under pressurized no-flow conditions after the development of myogenic tone or constriction with the thromboxane A2 mimetic U46619.

2. Relaxations of WKY and SHR arteries following development of myogenic tone did not differ and were not significantly influenced by indomethacin alone (10 μmol/l) or in combination with Nω-nitro-l-arginine (l-NNA, 0.1 mmol/l). Maximum relaxations were significantly attenuated by 30 mmol/l K+ in the SHR, from 85 ± 7% (n = 11) to 20 ± 8% (n = 8), P < 0.001, and in the WKY from 86 ± 5% (n = 9) to 39 ± 14% (n = 8), P < 0.01.

3. Relaxations following constriction with U46619 were also similar in both rat strains. Maximum relaxations were 50 ± 11% (n = 8) in SHR and 60 ± 7% (n = 6) in WKY. Indomethacin did not influence these relaxations. The combination of indomethacin and l-NNA attenuated relaxations in WKY (P < 0.01), but in the SHR the attenuation did not achieve statistical significance (P = 0.07) compared with controls; the maximum responses were reduced to 25 ± 7% (n = 8) and 14 ± 11% (n = 6) in the SHR and WKY respectively, but only in the WKY was this reduction significant (P < 0.05).

4. These data demonstrate that, under control conditions, SHR and WKY coronary arteries relax equally effectively, regardless of mode of contraction, and also that the mechanism of acetylcholine-mediated relaxation differs according to the mode of contraction. Acetylcholine relaxes myogenic tone by a K+-sensitive mechanism in both WKY and SHR, consistent with a role for endothelium-derived hyperpolarizing factor; NO contributes substantially to the relaxation of U46619-induced tone by acetylcholine in the WKY, but to a diminished extent in the SHR.

5. These data indicate that the choice of vasoconstrictor agent is of critical concern when assessing mechanisms of endothelium-dependent relaxation and abnormalities thereof in hypertension.
Changes in Both the Membrane and the Enzyme Content of Individual Zymogen Granules are Associated with Sodium Taurocholate-Induced Pancreatitis in Rats
Authors: Manso Manuel A. , Orfao Alberto , Tabernero M. Dolores , Vicente Secundino , De Dios Isabel
Published: August 2015

1. After monitoring the changes associated with necrotizing acute pancreatitis in rats from early stages to 24 h after infusion of 5% sodium taurocholate in the choledocus, we characterized by flow cytometry the zymogen granules that still remained in the pancreas 18 h after sodium taurocholate infusion in order to explore whether alterations in the enzyme content and/or in the composition of the granule membrane could be related to the intracellular mechanisms involved in the development of necrotizing acute pancreatitis.

2. Significant increases in the haematocrit, plasma and peritoneal exudate amylase levels and oedema were observed from the third hour after 5% sodium taurocholate infusion onwards. Additionally, cell alterations such as hypergranulation, dilatation of the endoplasmic reticulum and autophagic vacuoles were found 3 and 6 h after infusion. DNA decrease, degranulation and necrosis were observed from 12 h after sodium taurocholate infusion onwards.

3. Flow cytometric measurements of zymogen granules isolated from rat pancreas 18 h after 5% sodium taurocholate infusion revealed a significant decrease in their internal complexity without major changes in their size. Double staining of granules with Tetragonolobus purpureus lectin, which specifically binds l-fucose and specific anti-trypsinogen or anti-amylase antisera, showed that rats with induced pancreatitis have decreased amounts of l-fucose in the membrane glycoconjugates and lower enzyme content (70% and 30% less for trypsinogen and amylase respectively).

4. A decrease in l-fucose in the membrane together with membrane abnormalities observed by electron microscopy in zymogen granules isolated 18 h after sodium taurocholate infusion indicate an altered synthesis of new granules or lysis of preformed zymogen granules which would favour differential loss of granular enzymes, mainly tripsinogen, which in turn could increase the severity of disease.
Differential Regulation of Ventricular Adrenomedullin and Atrial Natriuretic Peptide Gene Expression in Pressure and Volume Overload in the Rat
Authors: Kaiser Michael , Kahr Ole , Shimada Yasuyuki , Smith Pamela , Kelly Martin , Mahadeva Harin , Adams Matthew , Lodwick David , Aalkjaer Christian , Avkiran Metin , Samani Nilesh J.
Published: August 2015

1. Adrenomedullin is a recently discovered vasodilating and natriuretic peptide whose physiological and pathophysiological roles remain to be established. Like atrial natiuretic peptide adrenomedullin is expressed in the left ventricle. Ventricular expression of atrial natriuretic peptide is known to be markedly increased by volume or pressure overload. In this study we investigated whether ventricular expression of adrenomedullin is similarly stimulated under such conditions.

2. Ventricular adrenomedullin and atrial natriuretic peptide mRNA levels as well as those of a loading control mRNA (glyceraldehyde-3-phosphate dehydrogenase) were quantified by Northern blot analysis in (a) rats with severe post-infarction heart failure induced by left coronary ligation at 30 days post-surgery and (b) in rats with pressure-related cardiac hypertrophy induced by aortic banding at several time points (0.5, 1 and 4 h, and 1, 4, 7 and 28 days) after surgery. Levels were compared with those in matched sham-operated controls.

3. The mRNA level of atrial natriuretic peptide was markedly increased (8–10-fold) in the left ventricle of animals with post-infarction heart failure. In contrast, there was only a modest (40%) increase in the level of adrenomedullin mRNA. In rats with pressure-induced cardiac hypertrophy the ventricular level of atrial natriuretic peptide mRNA was again markedly increased (maximum 10-fold). The increase was first noticeable at 24 h post-banding and persisted until 28 days. In contrast, there was no change in adrenomedullin mRNA level compared with sham-operated rats at any time point.

4. Despite having similar systemic effects, the expression of adrenomedullin and atrial natriuretic peptide in the left ventricle is differently regulated. The findings imply distinct roles for the two peptides. The results do not support an important role for ventricular adrenomedullin expression in the remodelling process that occurs during the development of cardiac hypertrophy but suggest that ventricular adrenomedullin participates in the local and/or systemic response to heart failure
Neutrophil Cathepsin G Modulates Platelet P-Selectin Expression and Inhibits P-Selectin-Mediated Platelet-Neutrophil Adhesion
Authors: Ilton Marcus K. , Taylor Marcia L. , Misso Neil L. A. , Thompson Philip J. , Hung Joseph
Published: August 2015

1. Close contact between platelets and neutrophils modulates their cellular interactions in thrombotic and inflammatory states, with stimulation of P-selectin expression on platelets by agonists such as thrombin and neutrophil-derived cathepsin G being critical in mediating platelet—neutrophil adhesion. This study compared the effects of thrombin and cathepsin G on platelet P-selectin expression and on P-selectin-mediated platelet—neutrophil adhesion.

2. Washed platelets and platelet—neutrophil mixed cell suspensions (platelet/neutrophil ratio, 10:1) were incubated with either the supernatant of activated neutrophils, purified cathepsin G or thrombin. Platelet P-selectin expression and platelet adhesion to neutrophils was quantified by flow fluorocytometric analysis.

3. The supernatant from activated neutrophils stimulated platelet P-selectin expression comparable to that produced by purified cathepsin G or thrombin. P-selectin expression induced by both activated neutrophil supernatant and purified cathepsin G was completely inhibited by α1-antichymotrypsin, a specific inhibitor of cathepsin G. Unlike thrombin, which induced maximum platelet P-selectin expression by 10 min, sustained to 120 min, cathepsin G induced an initial large increase in platelet P-selectin expression, followed by a progressive reduction over 30–60 min to baseline levels.

4. Co-incubation of neutrophils with thrombin-stimulated platelets resulted in a significant increase in P-selectin-mediated platelet—neutrophil adhesion, which was completely inhibited by preincubation of neutrophils with anti-sialyl Lewisx monoclonal antibody. Thrombin produced maximum platelet—neutrophil adhesion by 10 min which remained stable over 120 min. In contrast, cathepsin G-stimulated platelets did not adhere to neutrophils over 120 min of co-incubation. Addition of cathepsin G to thrombin-stimulated platelets caused a progressive reduction over 30–60 min to baseline levels of platelet—neutrophil adhesion.

5. Neutrophil-derived cathepsin G is a potent platelet activator, but unlike thrombin it causes a time-dependent loss of platelet P-selectin expression and inhibits P-selectin-mediated platelet—neutrophil adhesion. Therefore, cathepsin G may modulate thrombin-mediated platelet—neutrophil adhesive interactions in inflammation and thrombosis.