bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive changes in cardiac myosin heavy chain and creatine kinase isozymic profiles in rats native of altitude
Authors: Letout A. , Solares‐Espinoza M. , Mateo P. , Koulmann N. , Bahi L. , Serrurier B. , Favier R. , Ventura‐Clapier R. , Bigard X. 
Published: May 2005

AbstractAim: The developmental changes in the myosin heavy chain (MHC) profile, creatine kinase (CK) and lactate dehydrogenase (LDH) activities and isozyme expression occurring in heart were examined in rats born and living at altitude (La Paz, Bolivia, 3700 m, HLP) for 16 generations. We hypothesized that HLPrats respond differently to hypoxia than rats born and living at sea level, and secondarily exposed to altitude during 3 weeks (H3W).Methods: The cardiac expression of MHC, CK and LDH was studied in left (LV) and right ventricle (RV) of HLPanimals 1, 2, 3, 4 and 18 weeks after birth, and compared with control normoxic (C groups) and H3Wanimals.Results: Rats secondarily exposed to hypoxia showed a lowerα‐MHC content than C or HLPrats in both LV and RV, 3 weeks after birth (P < 0.05), consistent with a delay in the maturation of the heart contractile phenotype. A global increase in the total CK activity was observed in the LV of H3Wanimals in comparison with C rats (P < 0.05), while no change was reported in HLPanimals. In both ventricles, M‐LDH activity was higher in H3Wthan in HLPand C rats (P < 0.05). The relative amount ofα‐MHC decreased by 20% in RV of 18‐week‐old HLPand H3Wrats in comparison with C animals, consistent with the hypoxia‐induced ventricular enlargement (P < 0.01). An increased activity of the foetal B‐CK subunit was observed in both LV and RV of H3Wrats in comparison with HLPand C animals (P < 0.05).Conclusion: This study demonstrates that rats native and living at altitude for several generations present some features relevant to genetic selection to altitude.
Effects of acute hypercalcaemia on blood pressure in subjects with and without parathyroid hormone secretion
Authors: Kamycheva E. , Jorde R. , Haug E. , Sager G. , Sundsfjord J. 
Published: May 2005

AbstractAim:  Acute hypercalcaemia increases the blood pressure, but the mechanism is uncertain. It may partly be the result of the concomitant fall in parathyroid hormone (PTH) secretion as PTH has been reported to have a vasodilator effect. To elucidate this, we infused calcium intravenously in subjects with and without PTH secretion.Methods:  Seven thyroparathyroidectomized subjects with undetectable PTH levels and 10 controls were studied twice, once with a calcium clamp technique that increased plasma ionized calcium in two steps of 0.1 mmol L−1, each step lasting 60 min, and once with a placebo infusion.Results:  On the placebo day, blood pressure and all other variables were unaffected in both groups. On the calcium day, systolic blood pressure increased gradually and significantly from end of baseline till end of the calcium infusion in the controls (123.5 ± 19.8 and 134.2 ± 17.6 mmHg, P < 0.004) but not in the thyroparathyroidectomized subjects (124.9 ± 15.7 and 126.0 ± 20.6 mmHg, P = ns). Serum PTH levels fell promptly in the controls, and in both groups there was a significant increase in serum phosphate. The diastolic blood pressure and pulse rate, and the plasma adrenaline and noradrenaline, plasma renin activity, and serum aldosterone levels were unaffected by the calcium infusion.Conclusion:  During acute hypercalcaemia the blood pressure increase appears unrelated to catecholamine secretion and the renin–aldosterone system, whereas the fall in PTH secretion may play a contributory role.
Improved insulin‐stimulated glucose uptake and glycogen synthase activation in rat skeletal muscles after adrenaline infusion: role of glycogen content and PKB phosphorylation
Authors: Jensen J. , Ruzzin J. , Jebens E. , Brennesvik E. O. , Knardahl S. 
Published: May 2005

AbstractAim:  Effects of in vivo adrenaline infusion on subsequent insulin‐stimulated glucose uptake and glycogen synthase activation was investigated in slow‐twitch (soleus) and fast‐twitch (epitrochlearis) muscles. Furthermore, role of glycogen content and Protein kinase B (PKB) phosphorylation for modulation insulin sensitivity was investigated.Methods:  Male Wistar rats received adrenaline from osmotic mini pumps (≈150 μg kg−1 h−1) for 1 or 12 days before muscles were removed for in vitro studies.Results:  Glucose uptake at physiological insulin concentration was elevated in both muscles after 1 and 12 days of adrenaline infusion. Insulin‐stimulated glycogen synthase activation was also improved in both muscles. This elevated insulin sensitivity occurred despite the muscles were exposed to hyperglycaemia in vivo. After 1 day of adrenaline infusion, glycogen content was reduced in both muscles; insulin‐stimulated PKB ser473 phosphorylation was increased in both muscles only at the highest insulin concentration. After 12 days of adrenaline infusion, glycogen remained low in epitrochlearis, but returned to normal level in soleus; insulin‐stimulated PKB phosphorylation was normal in both muscles.Conclusion:  Insulin‐stimulated glucose uptake and glycogen synthase activation were increased after adrenaline infusion. Increased insulin‐stimulated glucose uptake and glycogen synthase activation after adrenaline infusion cannot be explained by a reduction in glycogen content or an increase in PKB phosphorylation. The mechanisms for the improved insulin sensitivity after adrenaline treatment deserve particular attention as they occur in conjunction with hyperglycaemia.
Contribution of different Ca2+‐activated K+ channels to the first phase of the response to TRH in clonal rat anterior pituitary cells
Authors: Mørk H. K. , Haug T. M. , Sand O. 
Published: May 2005

AbstractAims:  Thyrotropin‐releasing hormone (TRH) induces biphasic changes in electrical activity, cytosolic free Ca2+ level ([Ca2+]i), and prolactin secretion from both clonal GH cells and native lactotrophs. The first phase of the TRH response is characterized by hyperpolarization because of activation of Ca2+‐activated K+ channels (KCa). In the present study, the relative contribution of BK, SK, and IK channels to the first phase of the TRH response in GH4 cells was assessed.Methods:  The expression of IK channels was confirmed by PCR with specific primers for SK4 (IK). The response to TRH was studied using the perforated patch technique and Ca2+ microfluoromety (fura‐2). The involvement of different KCa channels was estimated by employing the specific channel blockers iberiotoxin (BK), apamin (SK) and clotrimazole (IK).Results:  Application of 100 nm iberiotoxin, 1 μm apamin, and 10 μm clotrimazole reduced the peak value of the outward K+ current during the first phase of the TRH response by 33, 26, and 33%, respectively. Clotrimazole also shortened the duration of the outward current response by 60%, causing a reduction of total charge movement by 73%. All these toxin‐induced reductions were significant (P < 0.05). A combination of all three toxins abolished the current response almost completely.Conclusion:  All the three main types of KCa channels are involved in the first phase of the TRH response, with IK as the major contributor. This is the first demonstration of a dominant role of IK compared with BK and SK channels in excitable cells.
ERK1/2 inhibition prevents contraction‐induced increase in plasma membrane FAT/CD36 content and FA uptake in rodent muscle
Authors: Turcotte L. P. , Raney M. A. , Todd M. K. 
Published: May 2005

AbstractAim:  The purpose of this experiment was to investigate the role of extracellular signal‐regulated kinase 1/2 (ERK1/2) signalling in the contraction‐induced increase in muscle FA uptake.Methods:  Male Wistar rats (n = 41) were randomly assigned to either a resting or stimulated group. Within each group, animals were randomly assigned to receive PD‐98059, an inhibitor of MAP/ERK kinase 1/2 (MEK1/2), a kinase upstream of ERK1/2 and perfused with 550 μm palmitate, [14C]palmitate, 7 mm glucose, and no insulin. In the stimulated group, electrical stimulation (ES) of supramaximal trains of 100 ms was delivered every 2 s for 20 min.Results:  ERK1/2 phosphorylation was increased by 50% (P < 0.05) during ES but the contraction‐induced increase was prevented by the addition of PD‐98059. Glucose uptake increased by 3.6‐fold (P < 0.05) from rest to ES in muscle perfused without PD‐98059 and was not affected by the addition of PD‐98059 either at rest (P > 0.05) or during ES (P > 0.05). For a matched palmitate delivery, ES increased palmitate uptake by 35% (P < 0.05). PD‐98059 had no effect on palmitate uptake at rest but completely abolished the increase in palmitate uptake during ES. Plasma membrane FAT/CD36 protein content was increased by 38% during ES (P < 0.05) but the contraction‐induced increase was prevented by the addition of PD‐98059. AMPK activity was increased by ES (P < 0.05) but was unaffected by PD‐98059.Conclusion:  These results show for the first time that the increase in FA uptake and in plasma membrane FAT/CD36 protein content is mediated, at least in part, by the ERK1/2 signalling pathway during muscle contraction.
Immunomodulatory properties of human serum immunoglobulin A: anti-inflammatory and pro-inflammatory activities in human monocytes and peripheral blood mononuclear cells
Authors: Olas K , Butterweck H , Teschner W , Schwarz H P , Reipert B 
Published: May 2005

SummaryOur study investigated the immunomodulatory activities of human plasma-derived serum immunoglobulin (Ig)A. Previous findings seem contradictory indicating either pro- or anti-inflammatory activities. We used serum IgA purified from large plasma pools and studied the modulation of the release of cytokines and chemokines from resting and lipopolysaccharide (LPS, endotoxin)-stimulated human adherent monocytes and human peripheral blood mononuclear cells (PBMC). Our results indicate that IgA down-modulates the release of the pro-inflammatory chemokines monocyte chemoattractant protein (MCP) 1, macrophage inflammatory protein (MIP) 1α and MIP1β from LPS-stimulated PBMC and the release of MCP1, MIP1α and MIP1β from LPS-stimulated monocytes. Furthermore, we confirmed previous reports that plasma-derived serum IgA down-modulates the release of the pro-inflammatory cytokines, interleukin (IL)-6 and tumour necrosis factor (TNF)-α, from LPS-stimulated monocytes and PBMC, and up-regulates the release of IL-1 receptor antagonist (IL-1RA) from resting and LPS-stimulated monocytes and resting PBMC. This IgA-mediated up-regulation of IL-1RA is independent of the simultaneous up-regulation of IL-1β release, as shown by blocking the biological activity of IL-1β with a neutralizing antibody. On the other hand, we also found an IgA-induced pro-inflammatory activity, namely IgA-mediated up-regutation of the release of pro-inflammatory IL-1β as well as down-regulation of the anti-inflammatory cytokines IL-10 and IL-12p40 from LPS-stimulated monocytes and PBMC and a down-regulation of transforming growth factor (TGF)-β from resting and LPS-stimulated PBMC. We conclude that human serum IgA has both an anti-inflammatory and a pro-inflammatory capacity and this dual capacity might contribute to the feedback mechanisms maintaining a balance between pro-inflammatory and anti-inflammatory activities.
Measurement of peripheral B cell subpopulations in common variable immunodeficiency (CVID) using a whole blood method
Authors: Ferry B L , Jones J , Bateman E A , Woodham N , Warnatz K , Schlesier M , Misbah S A , Peter H H , Chapel H M 
Published: May 2005

SummaryRecent reports have described reduced populations of CD27+ memory B cells and increased percentages of undifferentiated B cells in peripheral blood of patients with common variable immunodeficiency (CVID). This work has prompted two attempts to classify CVID based on rapid flow cytometric quantification of peripheral blood memory B cells and immature B cells. Evidence to support the hypothesis that such in vitro B cell classification systems correlate with clinical subtypes of CVID is being sought. For the classification to be useful in routine diagnosis, it is important that the flow cytometric method can be used without prior separation of peripheral blood mononuclear cells (PBMC). We have examined 23 CVID patients and 24 controls, using both PBMC and whole blood, and find an excellent correlation between these methods. The reproducibility of the method was excellent. We classified the CVID patients by all three of the existing classifications, including secretion of immunoglobulin by B cells in vitro as described by Bryant, as well as the more recent flow cytometric classification methods. Only one patient changed classification as a result of using whole blood.
Defective prevention of immune precipitation in autoimmune diseases is independent of C4A*Q0
Authors: Arason G J , Kolka R , Hreidarsson A B , Gudjonsson H , Schneider P M , Fry L , Arnason A 
Published: May 2005

Summary
Increased prevalence of C4 null alleles is a common feature of autoimmune diseases. We have shown previously that complement-dependent prevention of immune precipitation (PIP) is defective in patients with systemic lupus erythematosus (SLE), and correlated this defect with C4A*Q0 and low levels of the C4A isotype. To further clarify the role of C4A in the aetiology of SLE, we now extend our studies to other diseases which have been associated with C4A*Q0. The frequency of C4A*Q0 was increased in Icelandic patients with coeliac disease (0·50; P &lt; 0·001), Grave's disease (0·30; P = 0·002) and insulin-dependent diabetes mellitus (0·23; P = 0·04) and in British patients with dermatitis herpetiformis (0·42; P = 0·002) and this was reflected in low levels of C4A. In spite of this, PIP was normal in these patients, and in marked contrast to our previous observations on connective tissue diseases, PIP measurements in these patient groups correlated more strongly with levels of C4B (r = 0·51, P = 0·0000004) than C4A. Patients with increased levels of anti-C1q antibodies had significantly lower PIP than patients without such antibodies (P &lt; 0·01) and a negative association of PIP with anti-C1q antibodies was also reflected in an increased prevalence (P = 0·006) and levels (P = 0·006) of anti-C1q antibodies in patients with subnormal PIP, as well as a negative correlation between PIP and anti-C1q antibodies (r = − 0·25, P = 0·02). These results show that the PIP defect cannot be explained by low levels of C4A alone and suggest that measurements of anti-C1q antibodies may be useful in future studies on the molecular cause of the PIP defect in autoimmune connective tissue disease.
The number of human peripheral blood CD4+ CD25high regulatory T cells increases with age
Authors: Gregg R , Smith C M , Clark F J , Dunnion D , Khan N , Chakraverty R , Nayak L , Moss P A 
Published: May 2005

SummaryAgeing is associated with evidence of immune deficiency and dysregulation. Key changes in the immune system with ageing include a progressive reduction in naive T cell output associated with thymic involution and peripheral expansion of oligoclonal memory T cells. These features are associated with evidence of impaired immune responsiveness both in vitro and in vivo, termed immune senescence. CD4+ CD25+ T cells have recently been recognized as mediators of peripheral immune regulation and play a role in the control of autoimmune and pathogen-specific immune responses. The significance of CD4+ CD25+ regulatory T cells in the context of immunosenescence is not known. We have investigated the number, phenotype and function of CD4+ CD25+ T cells in healthy volunteers over a wide age range. We demonstrate that the number of CD4+ CD25+ and CD4+ CD25high T cells in healthy volunteers increases with age. In both age groups CD4+ CD25+ T cells showed a phenotype consistent with that described for regulatory T cells. Further analysis of CD4+ CD25high T cells in young and elderly donors showed equivalent expression of intracellular CTLA-4 and surface expression of activation markers. In vitro, functional titration assays of CD4+ CD25high T cells demonstrated equivalent regulatory function in both young and elderly donors, with suppression of proliferation and cytokine production in response to polyclonal T cell stimulation. These observations demonstrate an increase in peripheral blood CD4+ CD25high regulatory T cells associated with ageing. The relevance of these expanded cells in relation to the immune senescence seen in the elderly as yet remains unclear.
Batch kinetics and modelling of ethanolic fermentation of whey
Authors: Zafar Salman , Owais Mohammad , Saleemuddin Mohammed , Husain Sattar 
Published: May 2005

SummaryThe fermentation of whey by Kluyveromyces marxianus strain MTCC 1288 was studied using varying lactose concentrations at constant temperature and pH. The increase in substrate concentration up to a certain limit was accompanied by an increase in ethanol formation, for example, at a substrate concentration of 10 g L−1, the production of ethanol was 0.618 g L−1 whereas at 50 g L−1 it was 3.98 g L−1. However, an increase in lactose concentration to 100 g L−1 led to a drastic decrease in product formation and substrate utilization. The maximum ethanol yield was obtained with an initial lactose concentration of 50 g L−1. A method of batch kinetics was utilized to formulate a mathematical model using substrate and product inhibition constants. The model successfully simulated the batch kinetics observed at S0 = 10 and 50 g L−1 but failed in case of S0 = 100 g L−1 because of strong substrate inhibition.
The effect of extrusion temperature and drying‐tempering on both the kinetics of hydration and the textural changes in extruded ready‐to‐eat breakfast cereals during soaking in semi‐skimmed milk
Authors: Sacchetti Giampiero , Pittia Paola , Pinnavaia Gian Gaetano 
Published: May 2005

SummaryReady‐to‐eat breakfast cereals were made by a two‐step extrusion‐cooking and toasting process. Before toasting the products were given a drying‐tempering step. Two process variables (extrusion temperature and moisture content before toasting) were manipulated in order to obtain products with different physical characteristics. Density, hardness, hydration kinetics and textural changes of the products during soaking were studied in order to analyse the influence of these variables on the product quality. Both the variables significantly affected the product quality indices such as hardness and density. The processing conditions had only a slight influence on product water uptake during hydration but a dramatic influence on product softening. The hydration and softening rates were negatively correlated with density. When density was equal samples extruded at different extrusion temperatures showed different water uptake and softening rates. Products with the same values of initial hydration rate showed different initial softening rates because of extrusion temperature.
Thoracic myelitis as a possible cause of myocardial infarction
Authors: LAPPEGÅRD K. T. , JUSTAD G. , PRYTZ J. F. , MANHENKE C. 
Published: May 2005

Abstract.During the course of an inflammatory process in the thoracic part of the spinal cord, a previously healthy male suffered two myocardial infarctions in separate coronary territories. A coronary angiogram revealed only minor wall changes in one coronary artery. We hypothesize that the myocardial infarctions may have been caused by vasospastic reactions secondary to his spinal cord pathology, and present the case report and a review of the literature.
Upregulation of the immune system in primary hypercholesterolaemia: effect of atorvastatin therapy
Authors: SAMPIETRO T. , BIGAZZI F. , ROSSI G. , DAL PINO B. , PUNTONI M. R. , SBRANA F. , CHELLA E. , BIONDA A. 
Published: May 2005

AbstractObjectives.  High levels of plasma high sensitivity C‐reactive protein (CRP), sensitive to therapy with statins, have been described in hypercholesterolaemia. In vitro evidence shows that CRP activates the complement system, which, in turn, leads to an increased expression of ICAM‐1. Our objectives were to verify whether primary hypercholesterolaemia (PHC) is associated with an upregulation of the inflammatory/immune response, and whether this is sensitive to atorvastatin.Methods and results.  We examined the levels of sICAM‐1, C3, C4 complement fractions in 48 patients with PHC, with (CAD group) or without (No‐CAD group) coronary artery disease (CAD) in comparison with a group of 48 healthy controls. The two patient groups were studied before and after atorvastatin therapy. Both hypercholesterolaemic groups showed higher mean values of sICAM‐1, C3 and C4 (P < 0.0001) when compared with the controls. The two groups of patients responded differently to atorvastatin therapy. After 3 months, the C3 levels normalized in both groups of patients (P < 0.02 compared with basal values); C4 was greatly reduced only in the CAD group (P < 0.01). After 12 months of therapy, in CAD group C3 mean levels were still significantly lower than baseline values (P < 0.01); a further decrease in the C4 values (P < 0.05 with respect to levels after 3 months of therapy) and also a substantial reduction in sICAM‐1 values (P < 0.001 with respect to basal values) were observed.Conclusions.  High plasma values of C3 and C4 in PHC cluster with high values of sICAM‐1, distinguish subjects with CAD and could be used to monitor the anti‐inflammatory effect of statin therapy in these patients.
Nurse‐recorded clinic and ambulatory blood pressures correlate equally well with left ventricular mass and carotid intima‐media thickness
Authors: NYSTRÖM F. , MALMQVIST K. , LIND L. , KAHAN T. 
Published: May 2005

Abstract.Objective.  To assess relationships between noninvasive ambulatory blood pressure (BP), clinic BP (mean value of three readings in the seated position measured by nurses), structural cardiac indices, intima‐media thickness of the common carotid artery and several hormones.Design.  Cross‐sectional study of 75 subjects with hypertension and left ventricular hypertrophy (HTH) according to echocardiography, 35 subjects with hypertension and normal left ventricular dimensions (HT) and 23 normotensive subjects (NT).Results.  We found an excellent correlation between mean 24‐h ambulatory BP and clinic BP, the r‐value for systolic BP being 0.82 and for diastolic levels 0.78 (both P < 0.0001). Clinic and ambulatory BP correlated equally well with left ventricular (LV) mass index (r‐values between 0.55 and 0.64, all P < 0.0001) and to intima‐media thickness of the carotid artery (r = 0.18–0.34, P < 0.01). The systolic white‐coat effect (clinic BP − day‐time BP) was higher in the HTH and HT compared with NT and was weakly correlated to LV mass index (r =0.18, P = 0.04). Nondippers (mean arterial night/day BP ratio of >0.9) had higher brain (6.1 ± 7.5 pmol L−1 vs. 3.7 ± 3.2 pmol L−1, P =0.01) and atrial (14 ± 3.4 pmol L−1 vs. 9.3 ± 5.4 pmol L−1, P = 0.04) natriuretic peptide levels, and also exhibited a lower ejection fraction (49 ± 8% vs. 57 ± 9%, P = 0.006), than dippers.Conclusion.  Clinic BP recordings performed by nurses as three measurements 1 min apart provide excellent relationship to target organ damage. Nondippers exhibited signs of a more advanced hypertensive organ damage than dippers which corresponds well with the poor prognosis linked to this condition.