Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data visualisation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMedDate not supplied

Direct diagnosis of carriers of Duchenne and Becker muscular dystrophy by amplification of lymphocyte RNA.

Rapid detection of deletion and duplication mutations that cause Duchenne and Becker muscular dystrophy was achieved in patients and carriers after amplification of small amounts of mRNA from peripheral blood lymphocytes. The entire coding region of the dystrophin mRNA was amplified in 10 sections by reverse transcription and nested polymerase chain reaction, and the products were directly visualised on acrylamide minigels with ethidium staining. Major structural gene mutations were identified by the appearance of a band of different size to that of the wild type. The altered band was readily detected in all patients and heterozygous relatives. This non-radioactive test of venous blood samples can be used for unambiguous and rapid identification of virtually all carriers of deletions or insertions within the dystrophin gene.

Base Sequence↗
PubMed1999

Radiological determination of the posterior limits of the temporal lobe for volumetric analysis.

The posterior peri-Sylvian area is the most highly lateralized part of the human brain due to its specialised role in language. Currently, there is no clearly defined posterior boundary of the temporal lobe which takes account of language lateralization and which can be reliably determined radiologically. However, there have been a number of recent advances in magnetic resonance technology including volume visualisation techniques which have as their goal the realistic three-dimensional representation of the brain which is acquired in two-dimensional slices. These have enabled the identification of precise macroanatomical and cytoarchitectural boundaries from which an efficient and reproducible posterior limit may be demarcated. Such limit standardisation is important for volumetric investigations of both neurological and psychiatric disease. Magnetic resonance imaging (MRI) scans of 20 normal subjects (10 male and 10 female), aged between 18 and 42 years, were acquired as part of a study of normal temporal lobe volume variation. In order to demonstrate the method of posterior limit placement, a thin slice (1.5 mm) 3D spoiled gradient magnetic resonance image of the brain of a 30 year-old right-handed male, without neurological disease, was acquired on a 1.5 tesla GE magnetic resonance machine. The data set was transferred via network to the hard disk of a 166 MHz Pentium processor PC. A software package called MEASURE allowed reformation of the data set in all three orthogonal planes. Then, using a high resolution algorithm, the brain was aligned along the newly proposed posterior plane which runs from the limit of the Sylvian fissure, identified on a 3D rendering, to the posterior/inferior splenium. It is hoped that this procedure will be utilised as a standard method for radiological determination of the limit of the posterior temporal lobe in order to allow volumetric measurements of this structure to be compared in a meaningful way.

Adolescent↗
PubMed1996

Combined use of proacrosin immunocytochemistry and autosomal DNA in situ hybridisation for evaluation of human ejaculated germ cells.

The recently reported human pregnancies and births after fertilising oocytes with round spermatids recovered from the ejaculate of men with non-obstructive azoospermia have underscored the need for a more accurate evaluation of the nuclear and cytoplasmic maturation status of ejaculated germ cells. In this study we describe our first experience with a method combining the immunocytochemical visualisation of proacrosin with autosomal DNA fluorescence in situ hybridisation (FISH) to assess ejaculated germ cells from patients with a spermiogenesis defect. The proacrosin immunoreactivity, analysed with the use of the monoclonal antibody 4D4, has been detected in cells of round spermatid size presenting a haploid FISH figure as well as in larger cells whose ploidy corresponds to primary and secondary spermatocytes. These observations are in agreement with previously published results obtained, with the use of the same antibody, by immunocytochemical analysis of histological sections of testicular tissue. All the cells of round spermatid size possessing proacrosin immunoreactivity were found to be haploid by FISH. On the other hand, some of the haploid cells of round spermatid size did not possess proacrosin immunoreactivity. The structural pattern of proacrosin immunoreactivity was highly variable both in spermatids and in younger spermatogenic cells. These data show that cell size is the main criterion to be used for the identification of ejaculated round spermatids, whereas the presence of the developing acrosome represents only an auxiliary criterion. The scoring of acrosomal development in ejaculated spermatids may be useful as part of pre-treatment diagnosis before the inclusion of infertile couples in a spermatid conception programme.

Acrosin↗
PubMed1999

Stress induced changes in transmitter release from sympathetic varicosities of the mouse vas deferens.

Activation of the sympathetic nervous system is an important component of the response to stress, but the effects of prolonged stress on sympathetic neurotransmission have not been assessed. In the present study we have examined the effect of 3 to 10 days exposure to stress induced by frequent handling and sham injections on neurotransmitter release from sympathetic varicosities of the mouse vas deferens. DiOC2(5)-fluorescence was used to visualise the sympathetic varicosities so that extracellular electrodes could be placed over known numbers of varicosities to monitor transmitter release using electrophysiological techniques. The frequency of excitatory junction currents (EJCs) increased with increasing duration of exposure to stress. The mean and maximum EJC amplitude significantly increased by 107% and 43%, respectively after 10 days of exposure to stress. The density of sympathetic varicosities innervating smooth muscle of the mouse vas deferens was not changed throughout the duration of the exposure to stress. The findings from this study demonstrate that the efficacy of transmitter release from the sympathetic varicosities is altered by repeated exposure of mice to stressful stimuli, such as handling and sham injections. Since such procedures are routine in many pharmacological experiments, it is important that investigators are aware of these changes so that due consideration is given when interpreting the data obtained from animals treated in this way.

Animals↗
PubMed2003

Purinergic signalling in the medullary mechanisms of respiratory control in the rat: respiratory neurones express the P2X2 receptor subunit.

ATP is involved in central respiratory control and may mediate changes in the activity of medullary respiratory neurones during hypercapnia, thus playing an important role in central chemoreception. The main objective of this study was to explore further the role of ATP-mediated signalling in respiratory control and central chemoreception by characterising the profile of the P2X receptors expressed by physiologically identified respiratory neurones. In particular we determined whether respiratory neurones in the rostral ventrolateral medulla (VLM) express P2X2 receptor subunits of the ATP-gated ion channel, since ATP currents evoked at recombinant P2X2 receptors are potentiated by lowering extracellular pH. Experiments were performed on anaesthetised (pentobarbitone sodium 60 mg kg-1 I.P., then 10 mg kg-1 I.V. as required), gallamine-triethiodide-treated (10 mg kg-1 I.V., then 2-4 mg kg-1 h-1 I.V.) and artificially ventilated rats. The VLM respiratory neurones were classified according to the timing of their discharge pattern in relation to that of the phrenic nerve and by the exclusion of pump cells from the study population; these were labelled with Neurobiotin using the juxtacellular method, and visualised with fluorescence microscopy. It was found that a substantial proportion of the VLM respiratory neurones express the P2X2 receptor subunit. P2X2 receptor subunit immunoreactivity was detected in approximately 50 % (six out of 12) of expiratory neurones and in approximately 20 % (two out of 11) of neurones with inspiratory-related discharge (pre-inspiratory and inspiratory). In contrast, no Neurobiotin-labelled VLM respiratory neurones (n = 19) were detectably immunoreactive for the P2X1 receptor subunit. Microionophoretic application of ATP (0.2 M, 20-80 nA for 40 s) increased the activity of approximately 80 % (13 out of 16) of expiratory neurones and of approximately 30 % (five out of 18) of VLM neurones with inspiratory-related discharge. These effects were abolished by the P2 receptor blocker suramin (0.02 M, 80 nA), which also reduced the baseline firing in some expiratory neurones. These data indicate that modulation of P2X2 receptor function, such as that evoked by acidification of the extracellular environment during hypercapnia, may contribute to the changes in activity of the VLM respiratory neurones that express these receptors.

Adenosine Triphosphate↗
PubMed1992

Multiple mitochondrial DNA deletions in an elderly human individual.

We have used the polymerase chain reaction (PCR) to study deletions in the mitochondrial DNA (mtDNA) of an elderly human individual. An extended set of PCR primers has been utilised to identify 10 mitochondrial DNA deletions in a 69-year-old female subject with no known mitochondrial disease. The particular deletions visualised as PCR products depended on the primer pairs used, such that the more distantly separated PCR primers enabled visualisation of larger deletions. Some deletions were common to the heart, brain and skeletal muscle, whereas others were apparently specific to individual tissues. DNA sequencing analysis of PCR products showed that short direct repeat sequences (5 to 13 bp) flanked all deletion breakpoints; in most cases one copy of the repeat was deleted. It is proposed that the accumulation of such multiple deletions is a general phenomenon during the ageing process.

Aged↗
PubMed2005

Structural changes of benzylether derivatives of vesamicol and their influence on the binding selectivity to the vesicular acetylcholine transporter.

18F labelled vesamicol analogues, which bind to the vesicular acetylcholine transporter (VAChT) in central cholinergic nerve terminals, are expected to be potential radioligands for the visualisation of cholinergic transmission deficits via positron emission tomography (PET). In this report the regioselective synthesis of five novel vesamicol analogues as well as their in vitro binding properties to the VAChT are described. Beside having the 4-fluorobenzylether-substitution at the cyclohexyl ring as an unique structural feature, the new compounds are additionally modified at the phenyl and piperidine moiety of the vesamicol skeleton. The affinity and selectivity to the VAChT were analysed by competitive binding studies using tritium labelled radioligands. The VAChT affinities (Ki-values) of the novel compounds were estimated ranging between 7.8+/-3.5 nM and 161.6+/-17.3 nM, thus some of them are binding with higher affinity to the transporter than vesamicol. However, the compounds tested demonstrated also affinities to the sigma receptors sigma1 and sigma2 ranging between 4.1+/-1.5 nM and 327.5+/-75.9 nM. Nevertheless, these data provide the basis for future structure-binding-studies and further underline the potential and usefulness of vesamicol analogues for imaging of the VAChT.

Animals↗
PubMed2005

New positron emission tomography tracer [(11)C]carvedilol reveals P-glycoprotein modulation kinetics.

Imaging of P-glycoprotein (P-gp) function in the blood-brain barrier (BBB) may support development of strategies, which will improve drug delivery to the brain. [(11)C]verapamil has been developed as a positron emission tomography (PET) tracer, to image P-gp function in vivo. Ideally, for the purpose of brain imaging, tracers should have a log P between 0.9 and 2.5. The beta-receptor antagonist carvedilol is a P-gp substrate with a log P=2.0, and can be labeled with [(11)C]. The aim of this study was to determine whether the P-gp substrate [(11)C]carvedilol can be used as a PET tracer for visualisation and quantification of the P-gp function in the BBB. Cellular [(11)C]carvedilol accumulation in GLC(4), GLC(4)/P-gp, and GLC(4)/Adr cells increased three-fold in the GLC(4)/P-gp cells after pretreatment with cyclosporin A (CsA) whereas no effect of MK571 could be determined in the GLC(4)/Adr cells. Ex vivo [(11)C]carvedilol biodistribution studies showed that [(11)C]carvedilol uptake in the brain was increased by CsA. [(11)C]carvedilol uptake in other organs was not affected by CsA. Autoradiography studies of rat brains showed that [(11)C]carvedilol was homogeneously distributed over the brain and that pretreatment with CsA increased [(11)C]carvedilol uptake. In vivo PET experiments were performed with and without P-gp modulation by CsA. P-gp mediated transport was quantified by Logan analysis of the PET data, calculating the distribution volume (DV) of [(11)C]carvedilol in the brain. Logan analysis resulted in excellent fits, revealing that [(11)C]carvedilol is not trapped in the brain. Brain DV of [(11)C]carvedilol showed a dose-dependent increase of maximal three-fold after CsA pretreatment. Above 15 mg kg(-1), no change in DV was found. Compared to [(11)C]verapamil less CsA was needed to reach maximal DV, suggesting that [(11)C]carvedilol kinetics is a more sensitive tool to in vivo measure P-gp function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Evaluation and visualisation of perceived thermal conditions.

Investigations have been made on ways to evaluate and visualise the perceived thermal climate. Thermal interaction with windows, heating, ventilation and seating influence the occupant's thermal situation. When this information on the physical thermal climate is linked together with human thermal sensation in "comfort-zone diagrams", valuable knowledge about the thermal situation can be visualised. Thermal manikin measurements of local climate disturbances with two different thermal manikins are found to be well correlated with the thermal sensation experienced by panels of subjects exposed to the same conditions. Differences both in manikin shape and construction, as well as testing conditions and panel members, make limit lines differ at some points. Comfort diagrams can be defined by equivalent temperature (t(eq)) limit lines; however, a consequence of individual and experimental variations is that it is not an optimal solution to have diagrams with absolute limit lines, rather a range of t(eq) values, forming new "comfort-zone diagrams". This improvement provides a more appropriate base for assessment of a complex local thermal climate, and opens up the possibility of a general profile that can be used with different manikins, possibly also different methods, in a variety of environments. However, more data from validation experiments with subjects and different methods will contribute to the development of a more general evaluation concept.

Air Conditioning↗
PubMed2002

Echo-planar magnetic resonance imaging of Gaviscon alginate rafts in-vivo.

Liquid Gaviscon and Gaviscon Advance are established reflux suppressant formulations. This study describes the use of echo-planar magnetic resonance imaging (EPI) to visualise non-invasively intragastric alginate rafts of Liquid Gaviscon and Gaviscon Advance in healthy subjects. Secondly, the feasibility of using relaxation rate (T2(-1)) measurements to monitor changes in the physicochemical properties of the rafts in-vivo is evaluated. Six subjects ingested 500 mL of a liquid meal and received a single dose of 20 mL Liquid Gaviscon or 10 mL Gaviscon Advance on 2 separate visits each and were imaged every 15 min. An alginate raft was observed in the stomach for all subjects and both treatments. The raft was observed to consist of a few large fragments on the majority of the scans for both products. At t = 60 min a raft was still present in all cases. Three-dimensional volume reconstructions showed, for the first time, the spatial distribution of the rafts within the gastric lumen. The T2(-1) data showed potential for assessment of dynamic changes in the physicochemical properties of the alginate rafts in-vivo. We conclude that EPI shows great potential in assessing alginate rafts formation in-vivo.

Adult↗
PubMed1992

Natural course of Crohn's disease after ileocolic resection: endoscopically visualised ileal ulcers preceding symptoms.

Forty two Crohn's disease patients were followed up after ileocolic resection with regard to symptoms and endoscopic appearance of the ileocolic anastomosis. Twenty eight patients resected because of colonic neoplasm served as controls. In all the Crohn's disease patients the ileal resection margin was disease free macroscopically at operation. In addition, intraoperative ileoscopy was performed in 13 and no sign of residual inflammation in the neoterminal ileum was seen. Endoscopy soon after surgery often showed preanastomotic ileal ulceration before symptoms appeared, whereas no anastomotic lesions were observed in the controls. Thus, 22 of 30 Crohn's disease patients examined had ulceration of the anastomotic area after three months, but only 10 had developed symptoms indicating relapse (73 v 33%). Corresponding figures in the 30 patients examined after one year were 93 v 37%, and in 14 patients after three years they were 100 and 86% respectively. The inflammatory lesions in all cases were preanastomotic, in the neoterminal ileum, and showed time related progression from aphthae to larger ulcers and stricture. The study suggests that endoscopically observed inflammatory lesions that appear soon after ileocolic resection for Crohn's disease signify new inflammation and not residual, persistent disease or incomplete anastomotic healing. The data further suggest that despite clinical remission after apparently radical intestinal resection, the bowel is permanently inflamed in Crohn's disease.

Adolescent↗
PubMed2004

Effect of laryngoplasty on respiratory noise reduction in horses with laryngeal hemiplegia.

REASONS FOR PERFORMING STUDY: Laryngoplasty is the technique of choice for treatment of laryngeal hemiplegia, with the aim of improving airway function and/or eliminating respiratory noise. However, there are no quantitative data in the literature describing the effect of laryngoplasty on upper airway noise or its relationship to upper airway mechanics in horses with laryngeal hemiplegia. OBJECTIVES: To determine whether laryngoplasty reduces respiratory noise in exercising horses with laryngeal hemiplegia; and to establish whether the degree of upper airway obstruction can be predicted by upper airway noise, or the degree of arytenoid abduction correlated with airway obstruction and noise production. METHODS: Six Standardbred horses with normal upper airways during maximal exercise were used. Respiratory sounds and inspiratory transupper airway pressure (Pui) were measured in all horses before and after induction of laryngeal hemiplegia and 30, 60 and 90 days after laryngoplasty. Inspiratory sound level (SL) and the sound intensity of the 3 inspiratory formants (F1, F2 and F3, respectively) were measured using a computer-based sound analysis programme. The degree of abduction was graded by endoscopic visualisation 1, 30, 60 and 90 days post operatively. Linear regression analysis was used to determine correlations between Pui, sound indices and grades of arytenoid abduction. RESULTS: In laryngeal hemiplegia-affected horses, Pui, inspiratory SL and the sound intensity of F1, F2 and F3 were significantly increased. At 30 days following laryngoplasty, the sound intensity of F1 and Pui returned to baseline values. The sound intensities of F2, F3 and SL were significantly improved from laryngeal hemiplegia values at 30 days post operatively, but did not return to baseline at any measurement period. Sound level, F2 and F3 were significantly correlated with Pui (P<0.05), but the correlations were weak (r2 = 0.26, 035 and 0.40, respectively). Grade of abduction and F2 were positively and significantly correlated (P<0.006, r2 = 0.76). Grade of arytenoid abduction and Pui were not correlated (P = 0.12). CONCLUSIONS: Laryngoplasty reduced inspiratory noise in laryngeal hemiplegia-affected horses by 30 days following surgery, but did not return it to baseline values. While upper airway noise and Pui were correlated, this relationship was insufficiently strong to predict Pui from noise in individual animals. The degree of arytenoid abduction was not correlated with Pui, but was positively correlated with noise production. POTENTIAL RELEVANCE: Laryngoplasty reduces upper airway noise in horses with laryngeal hemiplegia, but is not as effective as bilateral ventriculocordectomy in this regard, although respiratory noise reduction occurs more rapidly than with bilateral ventriculocordectomy. Residual noise during exercise cannot be used as a predictor of improvement in upper airway function in individual horses following laryngoplasty. The degree of arytenoid abduction obtained following surgery does not affect upper airway flow mechanics. Interestingly, we found that the greater the arytenoid abduction, the louder the respiratory noise.

Animals↗
PubMed1999

CT data sets surface extraction for biomechanical modeling of long bones.

In modelling applications such as custom-made implants design is useful to have a surface representation of the anatomy of bones rather than the voxel-based representation generated by tomography systems. A voxel-to-surface conversion process is usually done by a 2D segmentation of the images stack. However, other methods allow a direct 3D segmentation of the CT or MRI data set. In the present work, two of these methods, namely the Standard Marching Cube (SMC) and the Discretized Marching Cube (DMC) algorithms, were compared in terms of local accuracy when used to reconstruct the geometry of a human femur. The SMC method was found to be more accurate than the DMC method. The SMC method was capable of reconstructing the inner and outer geometry of a human femur with a peak error lower than 0.9 mm and an average error comparable to the pixel size (0.3 mm). However, the large number of triangles generated by the algorithm may limit its adoption in many modelling applications. The peak error of the DMC algorithm was 1.6 mm but it produced approximately 70% less triangles than the SMC method. From the results of this study, it may be concluded that three dimensional segmentation algorithms are useful not only in visualisation applications but also in the creation of geometry models.

Algorithms↗
PubMed2003

ER quality control can lead to retrograde transport from the ER lumen to the cytosol and the nucleoplasm in plants.

Quality control in the secretory pathway is a fundamental step in preventing deleterious effects that may arise by the release of malfolded proteins into the cell or apoplast. Our aims were to visualise and analyse the disposal route followed by aberrant proteins within a plant cell in vivo using fluorescent protein technology. A green fluorescent protein (GFP) fusion was detected in the cytosol and the nucleoplasm in spite of the presence of an N-terminal secretory signal peptide. In contrast to secreted GFP, the fusion protein was retained in the cells where it was degraded slowly, albeit at a rate much higher than that of the endoplasmic reticulum (ER)-retained derivative GFP-HDEL. The fusion protein could not be stabilised by inhibitors of transport or the cytosolic proteasome. However, the protein is a strong lumenal binding protein (BiP) ligand. Complete signal peptide processing even after long-term expression in virus-infected leaves rules out the possibility that the documented accumulation in the cytosol and nucleoplasm is because of the bypassing of the translocation pores. The data are consistent with the hypothesis that the fusion protein is disposed off from the ER via a retrograde translocation back to the cytosol. Moreover, accumulation in the nucleoplasm was shown to be microtubule dependent unlike the well-documented diffusion of cytosolically expressed GFP into the nucleoplasm. The apparent active transport of the GFP fusion into the nucleoplasm may indicate an as yet undiscovered feature of the ER-associated degradation (ERAD) pathway and explain the insensitivity to degradation by proteasome inhibitors.

Biological Transport↗
PubMed1987

Cross sectional echocardiographic assessment of great artery diameters in infants and children.

The pulmonary trunk and aortic root were measured on cross sectional echocardiograms in 173 normal subjects aged from one day to 15 years. Fifteen neonates were reexamined 3-6 days later. The great vessels were visualised in the parasternal long axis and short axis views. All measurements were made in end diastole and end systole by the leading edge method. The internal diameter (inner surface to inner surface) of the pulmonary trunk was also measured. The diameters of the great vessels correlated best with the square root of body surface area. Individual variability in cardiac growth gave a wide scatter of normal values. This was controlled for by calculating the ratio of the pulmonary trunk to aortic root for each subject. This ratio showed little individual variability and, except for the neonatal period, was remarkably constant throughout infancy and childhood (1.06 (0.06)). In the first 24 hours of life the ratio of the pulmonary trunk to the aortic root was significantly larger (1.29 (0.12)) but within one week it decreased to the "normal" ratio found in the older age groups. These normal data should be useful in assessing patients with congenital heart disease, particularly those in whom pulmonary blood flow is abnormal.

Adolescent↗
PubMed2004

The genes for the helix-loop-helix proteins Id6a, Id6b, Id1 and Id2 are specifically expressed in the ventral and dorsal domains of the fish developing somites.

Muscle differentiation is inhibited by members of the Id family that block the transcriptional effect of myogenic bHLH regulators by forming inactive heterodimers with them. Also, Id proteins promote cell proliferation by interacting with key regulators of the cell cycle. In order to determine the role of Id-encoding genes during fish development and especially in early myogenesis, we examined the expression patterns of Id1, Id2 and two nonallelic Id6 (Id6a and Id6b)-encoding genes in developing trout embryos. These four Id paralogs were found to exhibit discrete expression in the developing nervous system and in the eye rudiment. During the segmentation process, Id6a, Id6b and Id1 were expressed in the tail bud, the paraxial mesoderm and the ventral and dorsal domains of neoformed somites. As the somite matured in a rostrocaudal progression, the labelling for Id1 transcripts rapidly faded whereas labelling for Id6 transcripts was found to persist until at least the completion of segmentation. By contrast, Id2 transcripts were visualised transiently only in dorsal domains of neoformed somites and strongly accumulated in the pronephros. The preferential localisation of Id6a, Id6b, Id1 and Id2 transcripts within ventral and/or dorsal extremes of the developing somites, suggests that these areas, which were the last ones to express muscle-specific genes, contain dividing cells involved in somite expansion.

Amino Acid Sequence↗
PubMed1988

Dual-label autoradiographic analysis of human skin fibroblast and myoblast proteins by two-dimensional polyacrylamide gel electrophoresis using immobilised pH gradients in the first dimension.

Horizontal two-dimensional polyacrylamide gel electrophoresis with immobilised pH gradients in the first dimension has been applied to the analysis of human skin fibroblast and muscle myoblast total cell proteins. Excellent two-dimensional separations of skin fibroblast proteins were obtained using pH 4-10 immobilised pH gradient gels with a long interelectrode distance (16 cm), but resolution was degraded, particularly of the more acidic proteins, by the use of shorter (10 cm) gels. Improved resolution of acidic and basic proteins was obtained using separate pH 4-7 and pH 7-10 immobilised pH gradient gels respectively in the first dimension. Two-dimensional protein maps of skin fibroblast proteins were visualised both by silver staining and by autoradiography of samples labelled synthetically with [35S]methionine. Horizontal two-dimensional electrophoresis, using pH 4-7 and pH 7-10 immobilised pH gradient gels in the first dimension, was applied to the analysis of protein samples from skin fibroblasts and muscle myoblasts dual-labelled synthetically with [35S]methionine and [75Se]selenomethionine in an attempt to identify sets of proteins specific to each cell type. In addition, two-dimensional maps or protein samples derived from normal individuals and patients with Duchenne muscular dystrophy were compared to search for protein changes associated with the disease state. Although sets of qualitative protein spot differences were observed by visual inspection of the two-dimensional gels, more rigorous qualitative and quantitative analysis of the patterns using a computerised analysis system will be required to obtain the maximum amount of information from these data.

Autoradiography↗
PubMed1993

Specific atrial overexpression of G protein coupled human beta 1 adrenoceptors in transgenic mice.

OBJECTIVE: The aim was to develop a transgenic mouse model of atrial beta 1 adrenoceptor overexpression in order to create atrial alteration of the receptor transduction system. METHODS: Transgenic founders were generated after microinjection of the transgene construct into the pronucleus of fertilised mouse eggs. Heterozygous progeny were screened for RNA expression of the human beta 1 adrenoceptor gene under the control of a 0.56 kb proximal promoter of the human atrial natriuretic factor. One line, out of the three obtained, was selected and further characterised for overexpression of the human beta 1 adrenoceptor. Polymerase chain reaction was employed to detect beta 1 adrenoceptor mRNA, and 125I-cyanopindolol (ICYP) binding assays were used to quantify receptors in heart membranes. A quantitative autoradiographic ICYP binding technique was also used to visualise atrial and ventricular beta adrenoceptors in heart sections. RESULTS: The human beta 1 adrenoceptor was overexpressed specifically in the atria of transgenic mice. The level of the beta 1 adrenoceptor was 5-10-fold higher in transgenic mice compared to basal murine beta 1 adrenoceptors in non-transgenic control mice. Left and right atrial receptor overexpression was confirmed by in vitro autoradiography. The human receptors were able to couple to the murine stimulatory G proteins (Gs), as shown by high affinity binding site dosage using the beta adrenoceptor agonist isoprenaline. Isoprenaline displacement studies allowed the determination of two different affinity sites, one of high affinity (KH = 5.8 nM), and one of low affinity (KL = 520 nM). When expressed in terms of protein density (fmol.mg-1), atrial transgenic beta 1 adrenoceptors displayed a threefold increase in high affinity sites (KH) as compared to control mice. Preliminary electrocardiographic data showed supraventricular premature beats in 6/14 transgenic mice v 2/16 control mice. CONCLUSIONS: These transgenic mice may provide a useful pharmacological tool to investigate the pathophysiological consequences of the overactivation of atrial beta 1 adrenoceptor-adenylyl cyclase signalling system.

Animals↗