PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “The Right to Reproduce”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 235 records · Page 13Linked to original sources
PubMed1994

Pattern recognition and self-correcting distance geometry calculations applied to myohemerythrin.

A topological list, consisting of segments of regular secondary structures and a list of buried and solvent accessible residues, is automatically predicted from multiple aligned sequences in a protein family. This topological list is translated into geometric constraints for distance geometry calculation in torsion angle space. A new self-correcting distance geometry method detects and eliminates false distance constraints. In an application to the four-helix bundle protein, myohem-erythrin, the right-handed global fold was correctly reproduced with a root-mean-square deviation of 2.6 A, when the topological list was derived from the X-ray structure. A predicted topological list, coupled with constraints from the residues in the active site of myohemerythrin, predicted the correct fold with a root-mean-square deviation of 4 A for backbone atoms.

Amino Acid Sequence↗
PubMed1990

Manual asymmetries in the reproduction of a 3-dimensional spatial location.

Two experiments examined differences in the reproduction of preselected arm positioning movements. In Experiment 1, subjects defined a position in right space with a right index finger, or a position in left space with the left index finger, and then attempted to reproduce the position with either the left or the right hand. Subjects were more accurate when vision was available and when the reproduction hand was the same as the criterion hand. Availability of vision reduced the same hand advantage. There were no accuracy differences between the left and right hands. Experiment 2 was designed to determine whether the left-left and right-right criterion and reproduction advantages evident in the no vision condition of the first experiment were accounted for by the two movements being made by the same hand or by being performed in the same space. The results demonstrated that accuracy depended primarily on whether movements were made with the same hand. No right/left hand advantage was observed. The absence of a right hand advantage in either experiment may be due to the spatial complexity of the task examined or to the relative absence of any temporal constraints.

Adult↗
PubMed1994

Relation between changes in blood flow of the contralateral coronary artery and the angiographic extent and function of recruitable collateral vessels arising from this artery during balloon coronary occlusion.

OBJECTIVES: The purpose of this study was to investigate changes in the magnitude of blood flow through the contralateral coronary artery in relation to the development of recruitable collateral vessels arising from this artery to supply a balloon-occluded coronary vessel. BACKGROUND: Recruitable collateral vessels have been shown to emerge suddenly to supply an occluded coronary artery, but their physiologic effect cannot always be predicted angiographically. METHODS: Twenty-four patients were studied during four successive balloon dilations for single left anterior descending coronary artery stenosis. Before and during each balloon occlusion, blood flow in the proximal right coronary artery was measured by intracoronary Doppler flow velocimetry and quantitative coronary angiography. Estimates of chest pain and ST segment elevation were also obtained. RESULTS: Fourteen patients developed angiographically visible recruitable collateral vessels (high grade in 6 [group III], low grade in 8 [group II]), whereas 10 patients (group I) did not. During the four successive balloon occlusions, the right coronary artery flow showed transient reproducible increases in group III (first occlusion 66.4 +/- 36.8%, fourth occlusion 64 +/- 23.9%, all p = 0.036), progressive increases in group II (from first occlusion 17.9 +/- 26.6% [p = 0.08] to fourth occlusion 60.4 +/- 35.9% [p = 0.014]) and no significant changes in group I. Between the first and the fourth occlusion, the severity of chest pain and the magnitude of ST segment elevation declined significantly in group II but did not change in groups I and III. CONCLUSIONS: During balloon coronary artery occlusion, the transient appearance of recruitable collateral vessels is associated with a transient increase in blood flow through the collateral donor artery. This increase in coronary flow appears to reflect collateral function better than the angiographic assessment, especially in patients with poor collateral vessel recruitment.

Adult↗
PubMed1986

The brain, time reversal and Libet's concept of antedating.

The brain produces an image of the world outside on its own inner world and should by rights record temporal relationships whose sequence reproduces the sequence of events observed. As, however, visual, auditory and somatic sensory impulses reach the brain after latent periods of differing duration, marked phase differences occur. One way of producing linear phase characteristics with latent periods of 100-500 ms is by means of phase shift and time reversal, referred to in more detail later. With this model it can be shown that Libet's hypothesis of "antedating" (Libet et al., 1979) is consistent in itself, that is, that it contains no inner contradictions (Honderich, 1984). Although there is no sure proof that these mechanisms actually exist, there is in fact no other way of achieving linear phase than by phase shift and time reversal. It must therefore to be assumed that they are present in the brain.

Brain↗
PubMedDate not supplied

Good clinical practice, a transparent way of life. A review.

Investigators are regarded as central to the concept of clinical trials. Apart from bearing scientific responsibility, they will be confronted with a great number of ethical dilemma's concerning, amongst others, the justification and design of the trial, subject selection and informed consent, and presentation of the trial results. The ethical principles of biomedical research should be observed in accordance with a consistent moral code. The moral code of Good Clinical Practice (GCP) was developed in order to rule out inconsistencies. The principal tenets are that clinical trials should be good science, verifiable, monitored, well documented, and that they comply with the highest ethical standards. The principles of GCP are the protection of the rights of human subjects, integrity and reproducibility of data, and transparency of conduct.

Clinical Trials as Topic↗
PubMedDate not supplied

MR gradient echo volumetric analysis of human cardiac casts: focus on the right ventricle.

PURPOSE: Our goal was to assess the utility of different imaging directions in volumetric studies of the heart with MRI, in particular to identify the optimal imaging plane for studies of the right ventricle. METHOD: We examined 12 sets of human four-chamber cadaveric cardiac casts. Gradient echo MRI was performed in four imaging planes: (a) perpendicular to the right ventricular inflow tract; (b) perpendicular to the right ventricular outflow tract; (c) in the left ventricular short axis view; and (d) in the axial view. The volumes of the right ventricle and other cardiac cavities were determined with the method of discs. The true cast volumes were measured with the water displacement technique. The agreement between true and measured volumes and the repeatability of image analysis were determined using the Bland-Altman method. RESULTS: There were no statistically significant differences between the measured and true right ventricular volumes irrespective of the imaging plane. The axial plane gave the smallest mean absolute difference from the true right ventricular volume (3.2 +/-2.2 ml) and also the best repeatability of volume analysis (0.2+/-1.6 ml). However, the other imaging planes performed nearly as well, and the differences across the planes were not statistically significant (p > 0.05). Also, in studies of the left ventricle and left and right atrium, the axial view appeared to give the best results, but differences across the imaging planes remained small. CONCLUSION: The present studies of human cardiac casts suggest that gradient echo MRI is well applicable to right ventricular volume measurements. Imaging the right ventricle in axial planes covering the entire heart gives good agreement with true right ventricular volumes and excellent analysis reproducibility. However, other imaging directions perform nearly as well, and thus selection of the imaging plane may not be of major importance to the accuracy of cardiac volume measurements with MR.

Analysis of Variance↗
PubMed2006

Mechanisms of atrial tachyarrhythmias following surgical atrial fibrillation ablation.

INTRODUCTION: Typical and atypical atrial flutters (AFLs) and atrial tachycardias (ATs) have been reported in patients with prior surgical atrial fibrillation ablation. The underlying mechanisms for this group of atrial tachyarrhythmias have not been well characterized and the efficacy of catheter ablation in their treatment is unknown. METHODS AND RESULTS: Twenty patients (6 females) with a surface ECG diagnosis of AFL or AT following surgical atrial fibrillation ablation underwent 26 electrophysiology studies. Patients manifesting sustained, organized, and beat-by-beat reproducible atrial electrical activity underwent complete right and left atrial catheter mapping and catheter ablation. One patient had no inducible tachyarrhythmia, while 5 patients had nonmappable arrhythmias. Nineteen of the 31 potentially mappable atrial tachyarrhythmias were completely characterized in 14 patients. The underlying mechanisms were macro-reentrant left AFL (n = 9), focal left AT (n = 3), typical right AFL (n = 6), and atypical right AFL (n = 1). Of the 19 completely characterized atrial arrhythmias, catheter ablation was performed for 18, and the procedure was successful for 13 of these. After a mean follow-up of 15 +/- 10 months, 15 of 20 patients (75%) were in sinus rhythm including 10 of 13 patients (77%) with AT/flutter ablation. Ten patients, including 6 following ablation, were maintaining sinus rhythm without antiarrhythmic medications. CONCLUSIONS: Patients with an ECG diagnosis of AFL or AT following surgical atrial fibrillation ablation may have multiple tachycardia mechanisms with the right or left atrium as the site of origin. Many of these rhythms may resolve with further maturation of surgical atrial fibrillation ablation (SAFA) lesions or be treatable with antiarrhythmic medication. However, persistent tachyarrhythmias can often be treated successfully with catheter mapping and ablation.

Atrial Fibrillation↗
PubMed1981

A new scintigraphic technique for assessment of right atrial function.

Gated radionuclide imaging with 99mTc-labeled red blood cells was employed to assess changes in right atrial (RA) volume in 17 subjects. Studies were repeated within two hours in five of 12 normal subjects and at two and ten days after infarction in five patients. Time-activity curves were generated for the RA and right ventricle (RV) from variable regions of interest defined by automatic edge detection. The RA time-activity curve exhibited four phases: filling, early emptying, equilibration, and late emptying. Repeated measurements of RA early emptying rates correlated closely in normals (r = 0.93). Early RA emptying and RV filling rates corresponded closely (r = 0.89). In four patients with infarction, the RA emptying rate was slowed on the first study but had normalized by 10 days. In a patient with inferior infarction and suspected RV infarction, the RA emptying rate was depressed and remained so for 10 days. Thus, relative changes in right atrial volume can be assessed reproducibly by a radionuclide technique, which is relatively independent of geometric assumptions. This technique offers great promise as a method to assess atrial function in health and disease.

Adult↗
PubMed1995

Collagenase-induced intrastriatal hemorrhage in rats results in long-term locomotor deficits.

UNLABELLED: BACKGROUND AND PURPOSE. Previous studies have shown that injection of the metalloproteinase collagenase directly into the caudate nucleus of rats causes an intracerebral hemorrhage. The purpose of the present study is to determine functional deficits associated with a collagenase-induced hemorrhagic lesion of the striatum. METHODS: Twelve adult rats received a 2-microL infusion of bacterial collagenase (0.5 U in saline) into the right striatum. The rotational response to apomorphine (1 mg/kg SC) administration was then examined at 1, 4, 7, 21, 35, and 70 days after the surgery. In addition to the rotational asymmetry studies, the initiation of stepping movements in each forelimb was determined 8 weeks after the collagenase injections. In the assessment of rotational asymmetry and stepping ability, an additional six control animals received unilateral injections of saline alone. After behavioral testing, brains were processed for neuropathological evaluation. RESULTS: A net ipsilateral rotation was noted at all posthemorrhage time periods. The average rotational asymmetries on these days were 14.57 +/- 2.9, 20.33 +/- 2.7, 19.99 +/- 4.4, 18.95 +/- 4.9, 17.03 +/- 4.9, and 14.4 +/- 4.7, respectively (data expressed as mean clockwise rotations per 5 minutes +/- SEM). The average number of steps initiated by the forelimb ipsilateral and contralateral to the lesion was 28.3 +/- 2.1 steps per minute and 13.6 +/- 1.5 steps per minute, respectively. This difference between left and right forelimb stepping was stable and reproducible for 3 consecutive days. Histological studies revealed a long-lasting hematoma cavity surrounded by dense reactive gliosis in the striatum. CONCLUSIONS: We conclude that collagenase-induced intrastriatal hemorrhage results in long-term locomotor deficits and is therefore a useful model for developing and assessing therapeutic approaches for the restoration of neurological function after intracerebral hemorrhage.

Animals↗
PubMed2000

An insole pressure measurement system: repeatability of postural data.

This study analyzed the ability of an in-shoe plantar pressure measurement system to provide repeatable measurements of postural sway data for both healthy and clinical patients. Each participant's in-shoe pressure data were recorded for three trials during each test session during quiet stance. Healthy individuals (n = 9) participated on three consecutive days while clinical participants (n = 5) were tested on one day. Nine response variables were measured to assess their postural stability. Intrasubject measures were evaluated using the Kerlinger reliability procedure. Values provided directly by the Parotec System for a single day of testing yielded the following average coefficients: r = 0.95 (left), r = 0.97 (right) with mean coefficient values from the three day tests of: r = 0.98 (left), r = 0.98 (right). Variables calculated from raw data on a single day produced mean coefficients of: r = 0.77 (left), r = 0.76 (right) and over three days of: r = 0.65 (left), r = 0.66 (right). The ability to record highly reproducible data of postural sway parameters should assist clinicians to treat patients more confidently for balance deficiencies.

Biomechanical Phenomena↗
PubMed1988

Noninvasive mapping of human motor cortex.

Human motor cortex was stimulated using brief, high-voltage electrical stimulation. Constant-voltage stimuli were delivered through a bipolar surface stimulator with the anode placed at multiple positions on the scalp and the cathode situated 2.5 cm anterior to the anode. Recordings were bilateral from the abductor pollicis brevis, tibialis anterior, and risorius. We averaged the amplitudes of three muscle responses obtained from stimulation of each scalp position and assigned the resultant value to that position. The findings in eight normal volunteers were similar and reproducible. The maximal responses of the right hand were obtained when stimulating over C3, of the left hand when stimulating over C4, of the right and left legs when stimulating over Cz, and of the right side of the mouth when stimulating over T3.

Adult↗
PubMed1989

Fundamentals of stereophotography in medicine.

Depth perception is given by binocular vision and it can be reproduced photographically by taking left and right pictures. However, the optimum separation between the views may not always correspond to the distance between our eyes, particularly in close-up work. Important applications of stereophotography in medicine are examined in this article as well as some of the fundamental principles and techniques for taking 3-D pictures and viewing the results.

Depth Perception↗
PubMed1999

Putting patient and family voice back into measuring quality of care for the dying.

Quality of care and quality of life change substantially for those with a serious chronic illness and nearing the end of their lives. As one dies, life takes on new shape-values change and things once ignored become more important. Existing quality of care measures do not attend to the changes in priorities or to dimensions that acquire new significance (e.g., Spirituality and transcendence). An important impediment to addressing the inadequacies in the evidence base for palliative care, improving shortcomings of care, and holding institutions or health care systems accountable for the quality of care is the lack of valid and reliable measurement tools. In this article, an overview is presented of an ongoing research effort to develop measurement tools which will utilize the patient and family perspective to measure the quality of care.

Decision Making, Organizational↗
PubMed2006

Recurrent severe mitral regurgitation due to left ventricular apical wall motion abnormality caused by coronary vasospastic angina: a case report.

A 76-year-old man developed congestive heart failure due to severe mitral regurgitation after episodes of vasospastic angina. Echocardiography demonstrated left ventricular apical akinesis with ballooning and deformity of the anterior mitral leaflet becoming concave toward the left atrium. The acetylcholine provocation test induced diffuse coronary vasospasm in the distal segments of both right and left coronary arteries and reproduced severe mitral regurgitation. Follow-up echocardiography demonstrated decreased mitral regurgitation with ameliorated apical wall motion. Coronary vasospasm remained refractory to antivasospastic medications and severe mitral regurgitation relapsed 1 month after discharge. Mitral valve annuloplasty with a Carpentier-Edwards physio ring was performed, and no recurrence of mitral regurgitation was observed despite some episodes of vasospastic angina. We speculate that vasospastic angina and the resultant apical wall motion abnormality caused tethering of the mitral subvalvular apparatus, leading to inappropriate mitral coaptation and severe regurgitation.

Aged↗
PubMed1991

[A modification for reducing measurement value spread with the Hertel exophthalmometer].

The concave part of Hertel's exophthalmometer which contacts the orbita functions like an inclined plane. Therefore, the measurement is sensitive against tilting and changing of the basic distance. We modified this contact surface into a right angle. The tangents at the contact points form a common line at right angles to the measurement direction. Reproducibility of measurements was studied on 10 patients who were measured by 5 to 12 different examiners with both instruments. Accuracy improved significantly by 57%.

Equipment Design↗
PubMed1985

Automated microscope image analysis in the cytological tumor diagnostics. Results on borderline-cases of mammary tumors.

50 fine-needle biopsies of mammary tumors (20 medullary carcinomas, 20 fibroadenomas, and 10 false negative judged cases) were studied by automated microscopic image analysis. Eight morphometric and densitometric features of the tumor cell nuclei were determined on Papanicolaou stained smears. It was analyzed whether smears false judged as negative can be rightly allocated as carcinomas by the automated method. The results of this study have shown that it was possible by means of three cell nucleus parameters (standard deviation of the area, mean area ratio, and skewness of the grey value gradient at contours) with 100% correct separation of the unequivocal cytologies into malignant and benign smears to recognize about 90% of the false judged smears rightly as carcinomas. The results are reproducible and can be obtained in a time of 2-5 min per smear. The first results show that the automated microscope image analysis may be a valuable tool in the diagnosis of borderline-cases of mammary tumors.

Adenofibroma↗
PubMed1983

Short-term hemodynamic results after right ventricular outflow tract reconstruction using a cusp-bearing transannular patch.

Correction of right ventricular outflow tract obstruction remains a challenge to cardiovascular surgeons. In order to relieve this obstruction and at the same time prevent or minimize pulmonary insufficiency, we inserted a cusp-bearing transannular patch (monocusp) in 14 patients. To test this objective, we restudied 13 of these patients 0.5 to 4 months postoperatively, including quantifying pulmonary insufficiency using an accurate videodensitometric method. In all patients a degree of pulmonary insufficiency ranging from 8% to 46% of total stroke volume (mean 22.7 +/- 10.6%) was measured, and in all but one a residual right ventricular outflow pressure gradient of 2 to 22 mm Hg (mean 10 +/- 7 mm Hg) was measured. There was an inverse relation between the degree of pulmonary insufficiency and both the pressure gradient (r = -0.89) and the ratio of the pulmonary valve ring diameter to monocusp depth (r = -0.67). An ideal reconstruction of the right ventricular outflow tract obstruction, without any postoperative pulmonary insufficiency and stenosis, was not achieved by the implantation of a monocusp in the described fashion. The postoperative results were acceptable in only a few patients. A reduction of pulmonary insufficiency seems to be associated with a small residual pressure gradient as well as a relatively small cusp size. Additional studies are necessary to further improve surgical correction of right ventricular outflow tract obstruction with reproducible and predictable results.

Adolescent↗