Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Torso”

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 163 records · Page 9Linked to original sources

Using principal-components regression to stabilize EMG-muscle force parameter estimates of torso muscles.

Models for estimating muscle force from surface electromyographic (EMG) recordings require parameter estimates with low intertrial variability. The inclusion of multiple muscles in multivariate statistical models can lead to multicollinearity, especially when there are significant correlations between synergist muscles. One result of multicollinearity is that parameter estimates are very sensitive to changes in the independent variables. This study compared the parameter variability of multiple regression and principal-components regression techniques when applied to a six muscle EMG analysis of the lumbar region of the torso. Nine subjects participated. Twenty-three percent of the traditional multiple-regression parameters had incorrect signs, but none of the principal-components regression parameters did. The principal-components regression technique also produced parameter estimates having an order of magnitude smaller parameter variability. It was concluded that principal-components regression is an effective method of mitigating the effect of multicollinearity in torso EMG models.

Adult↗

Moving dipole inverse solutions using realistic torso models.

A noniterative numerical solution for the potentials on the surfaces of a piecewise homogeneous volume conductor due to a current dipole is described. This forward solution has been used in electric and magnetic single moving dipole (SMD) inverse solutions that employ a torso volume conductor model whose boundaries are specified numerically. Thus, the volume conductor model used by the inverse solutions need not be limited to simple geometric shapes; torso models of realistic shape can be used.

Electric Conductivity↗

The effect of torso impedance on epicardial and body surface potentials: a modeling study.

Experimental results have been published that report marked changes in measured epicardial potentials when the conductivity of the material surrounding the heart is altered. These reports raise a question as to the validity of the traditional two step, equivalent cardiac source approach to modeling the forward problem of electrocardiology as the equivalent source calculation occurs in what is effectively an isolated cardiac region. In the physical situation the heart is surrounded by a torso that contains many different tissue types with different conductivities and is certainly not isolated. Here, a fully coupled model of the problem is employed where the electrical pathways are continuous from a cellular level through to the body surface. This model is used to investigate the effects that torso inhomogeneities have on epicardial and body surface potentials, including comparisons with a traditional two step approach. In particular, it is shown that adding lungs changes the epicardial potentials by 17%, which is consistent with the reported experimental results. In none of the tested situations did the equivalent source approach completely reproduce the fully coupled results, supporting the notion that a fully coupled approach is required to properly solve the forward problem of electrocardiology.

Abdomen↗

Genetic algorithm-neural network estimation of cobb angle from torso asymmetry in scoliosis.

Scoliosis severity, measured by the Cobb angle, was estimated by artificial neural network from indices of torso surface asymmetry using a genetic algorithm to select the optimal set of input torso indices. Estimates of the Cobb angle were accurate within 5 degrees in two-thirds, and within 10 degrees in six-sevenths, of a test set of 115 scans of 48 scoliosis patients, showing promise for future longitudinal studies to detect scoliosis progression without use of X-rays.

Abdomen↗

Penetrating wounds of the torso.

Penetrating trauma is on the increase as a result of interpersonal violence throughout the world. It is essential that military surgeons are familiar with such injuries and trained not only in the principles of their management, but also have first-hand operative experience before deployment in the field of conflict. More often than not, this experience is to be gained in the civilian urban setting in countries such as South Africa and the USA. The article addresses the first requirement--the principles of management--and outlines basic measures to enable those unfamiliar with penetrating wounds of the torso to make a reasonable and directed approach to dealing with these patients. It does not attempt to give definitive advice on specific injuries. It is organised according to anatomical regions, but emphasises that this is only in order to put shape to the article; penetrating injuries frequently having no respect for anatomical boundaries. Particular attention is drawn to difficult areas such as mediastinal injuries, and to modern concepts of 'damage control' surgery and the 'abdominal compartment syndrome'. The emphasis throughout is on how to get out of trouble and where particular danger spots may be anticipated. Reference will be made to the differences that may be expected within the military environment as opposed to the civilian setting, where rapid and (usually) safe evacuation to a well-equipped secure facility may not be possible. The article aims to raise the awareness of those involved in the care of patients with penetrating wounds of the torso that a methodical approach with a practised team of experienced individuals can salvage injuries which at first sight may seem terrifying or hopeless.

Abdominal Injuries↗

Role for tumor necrosis factor as mediator of lung injury following lower torso ischemia.

Ischemia and reperfusion of the ischemic lower torso lead to a neutrophil- (PMN) dependent lung injury characterized by PMN sequestration and permeability edema. This mimics the injury seen after infusion of tumor necrosis factor alpha (TNF), a potent activator of PMN and endothelium. This study tests whether TNF is a mediator of the lung injury after lower torso ischemia. Anesthetized rats underwent 4 h of bilateral hindlimb tourniquet ischemia, followed by reperfusion for 10 min, 30 min, 1, 2, 3, and 4 h (n = 6 for each time point). Quantitative lung histology indicated progressive sequestration of PMN in the lungs, 25 +/- 3 (SE) PMN/10 high-power fields (HPF) 10 min after reperfusion vs. 20 +/- 2 PMN/10 HPF in sham animals (NS), increasing to 53 +/- 5 PMN/10 HPF after 4 h vs. 23 +/- 3 PMN/10 HPF in sham animals (P less than 0.01). There was lung permeability, shown by increasing protein accumulation in bronchoalveolar lavage (BAL) fluid, which 4 h after reperfusion was 599 +/- 91 vs. 214 +/- 35 micrograms/ml in sham animals (P less than 0.01). Similarly, there was edema, shown by the lung wet-to-dry weight ratio, which increased by 4 h to 4.70 +/- 0.12 vs. 4.02 +/- 0.17 in sham animals (P less than 0.01). There was generation of leukotriene B4 in BAL fluid (720 +/- 140 vs. 240 +/- 40 pg/ml, P less than 0.01), and in three of six rats tested at this time TNF was detected in plasma, with a mean value of 167 pg/ml. TNF was not detectable in any sham animal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Multi-antioxidant supplementation does not prevent an increase in gut permeability after lower torso ischemia and reperfusion in humans.

BACKGROUND: An increase in gut permeability can have serious consequences leading to sepsis and multiple organ failure. After lower torso ischemia an increase in gut permeability is seen in both animals and humans. There is proof that this can be modified by antioxidant supplementation. METHODS: In this prospective, randomized study we have looked at the influence of a multiantioxidant supplementation regime, using allopurinol, vitamins E and C, mannitol and N-acetylcysteine, perioperatively. Twenty-two patients received standard treatment and 20 patients received supplementation. Gut permeability was determined using a double sugar test with lactulose and rhamnose. RESULTS: A significant increase in gut permeability was found neither in the non-treatment group (p = 0.012) nor in the treatment group (p = 0.006) after 6 and 24 h. No difference was found between the group receiving antioxidants and the standard treatment group. p = 0.93 6 h post clamp; p = 0.97 24 h post clamp. CONCLUSION: In this study we have not found an influence of multiantioxidant supplementation on gut permeability after lower torso ischemia. Possible explanations for this negative result are being discussed.

Acetylcysteine↗

Noninvasive recovery of epicardial potentials in a realistic heart-torso geometry. Normal sinus rhythm.

The inverse problem in electrocardiography implies the reconstruction of electrical events within the heart from information measured noninvasively on the body surface. Deduction of these electrical events is possible from measured epicardial potentials, and, thus, a noninvasive method of recovering epicardial potentials from body surface data is useful in experimental and clinical studies. In the present study, an inverse method that uses Tikhonov regularization was shown to reconstruct, with good accuracy, important events in cardiac excitation. The inverse procedure was employed on data obtained from a human-torso tank in which a beating canine heart was placed in the correct anatomical position. Comparison with the actual, measured epicardial potentials indicates that positions and shapes of potential features (maxima, minima, zero potential line, saddles, etc.) are recovered with good accuracy throughout the QRS. An error in position of up to 1 cm is typical, while amplitudes are slightly diminished. In addition, application was extended from the above setting, in which the geometry was precisely known and potentials at a large number of leads were measured accurately, to a situation that is more representative of clinical and experimental settings. Effects of inaccuracy in location of the position of the heart were examined. A stylized torso that approximates the actual geometry was designed, and its performance in the inverse computations was evaluated. A systematic method of reduction of the number of leads on the body surface was proposed, and the resulting lead configurations were evaluated in terms of the accuracy of inverse solutions. The results indicate that the inverse problem can be stabilized with respect to different types of uncertainties in measured data and offer promise in the use of the inverse procedure in clinical and experimental situations.

Animals↗

Role of neutrophil adherence receptors (CD 18) in lung permeability following lower torso ischemia.

Ischemia and reperfusion of the lower torso lead to leukotriene- and neutrophil (PMN)-dependent lung injury characterized by lung PMN sequestration, increased permeability, and noncardiogenic edema. It is thought that PMNs require adhesion to endothelium to alter barrier function. This study tests the role of CD 18, the PMN adherence receptor, in mediating lung permeability after lower torso ischemia and reperfusion. Anesthetized rabbits (n = 9) underwent 3 hours of bilateral hind limb ischemia. Ten minutes after the release of the tourniquets, plasma leukotriene B4 levels increased to 395 +/- 85 pg/ml, higher than 129 +/- 35 pg/ml in controls (n = 9, p less than 0.01). At this time there was a reduction in circulating white blood cells (x 10(3)), 3.56 +/- 0.49/mm3 relative to 6.07 +/- 0.61/mm3 in controls (p less than 0.01). PMNs were sequestered in the hind limbs, indicated by increased myeloperoxidase activity of 1.06 +/- 0.19 units/g compared with 0.56 +/- 0.09 units/g in controls (p less than 0.05). Four hours after tourniquet release, PMNs were sequestered in the lungs, 52 +/- 4 PMNs per 10 high-power fields, a value higher than 31.5 +/- 3 PMNs per 10 high-power fields in controls; bronchoalveolar lavage fluid protein content increased to 554 +/- 90 micrograms/ml relative to 277 +/- 46 micrograms/ml in controls; and there was lung edema, measured by increased wet weight-to-dry weight ratios of 5.19 +/- 0.10, higher than 4.29 +/- 0.21 in controls (all p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Phosphorylation of bicoid on MAP-kinase sites: contribution to its interaction with the torso pathway.

The Torso signal transduction pathway exhibits two opposite effects on the activity of the Bicoid (Bcd) morphogen: (i) Bcd function is repressed by Torso (Tor) at the anterior pole of the embryo leading to a retraction of the expression of many Bcd targets from the most anterior region of the embryo, where the Tor tyrosine kinase receptor is activated, and (ii) Bcd function is strengthened by Tor in a broader anterior region, as indicated by a shift of the posterior border of Bcd targets towards the anterior pole in embryos deprived from Tor activity. Anterior repression of Bcd targets was not observed in embryos lacking maternal contribution of D-sor, which acts downstream of Tor and encodes a MAP-kinase kinase. This indicates that the Ras signalling cascade is directly involved in this process, although the known transcriptional effectors of the Tor pathway, tll and hkb, are not (Ronchi, E., Treisman, J., Dostatni, N., Struhl, G. and Desplan, C. (1993) Cell 74, 347-355). Bcd is a good in vitro substrate for phosphorylation by MAP-kinase and phosphorylation of the protein occur in vivo on MAP-kinase sites. In the presence of a Bcd mutant that could no longer be phosphorylated by MAP-kinase, expression of Bcd targets remained repressed by Tor at the pole while strengthening of Bcd activity was reduced. These experiments indicate that phosphorylation of Bcd by MAP-kinase is likely to be required for the Tor pathway to induce its full positive effect on Bcd. This suggests that Tor signalling acts at a distance from the anterior pole by direct modification of the diffusing Bcd morphogen.

Amino Acid Sequence↗

Routine initial computed tomography of the chest in blunt torso trauma.

Computer tomography (CT) is an effective technique in the initial evaluation of the abdomen and head following blunt trauma. To evaluate the role of CT of the thorax, a prospective study comparing routine early thoracic CT scanning with initial chest roentgenogram (CXR) was carried out on 73 patients with blunt torso trauma undergoing concomitant abdominal CT examination. Initial CXR and CT scans were interpreted independently by radiologists in a blinded fashion. CXR diagnosed more bony injuries than CT, while the CT identified pulmonary contusions and effusions more accurately. Only those contusions diagnosed by CXR proved clinically significant. Patient treatment was changed in one case based on CT findings. In the absence of CXR findings, chest CT scanning frequently identifies abnormalities with limited clinical significance. Although more sensitive, CT of the thorax has a limited role in the initial emergent evaluation of victims of blunt torso trauma.

Abdominal Injuries↗

The effect of a back belt on torso motion--survey in an express package delivery company.

According to the Labor Standard Bureau of Japan, accidental back injuries accounted for about 60% of all occupational injuries and diseases in the last decade. The Ministry of Labor issued guidelines to prevent low back injuries in 1994 to address the problem. The use of back belts is recommended for some special working conditions but details on its proper use were not given. This study was planned to evaluate a newly developed back belt and was done at an express package delivery company where the incidence of low back injury was high. The BackTracker was used to evaluate the effect of the back belt on the range and velocity of torso motion. The results indicated that there were no significant differences in the range of motion (ROM) during flexion/extension, lateral bending, and rotation between with and without the belt. The maximum angular velocity (MAV) of flexion decreased significantly (average decrease: 30 +/- 28.3 degrees/sec) when the back belt was worn. The MAV of extension with belt showed a decreasing tendency though not significant. No notable trends were observed in the MAV, during lateral bending and rotation of the subjects while wearing and not wearing the belt. The results also indicated that the back belt affected differently the torso motion of each subject. This study suggested that this back belt could be useful for tasks with high velocity of flexion/extension and that proper instruction on the use of the back belt is needed for each worker.

Adult↗

Penetrating sledding injuries to the lower torso--2 case reports.

Sledding accidents are frequent and vary in severity. Penetrating sledding injuries are uncommon but may be devastating. Snow-racers--sleds with both steering and braking devices--may be associated with an increased rate of injury. The authors present 2 cases of lower-torso penetrating trauma associated with the use of snow-racers. Both cases involved penetration--of the perineum in one case and the inguinal area in the other--by wooden sticks. Both patients recovered fully after prompt surgical intervention. The authors suggest that the absence of a protective panel at the front of the snow-racer may result in the sledder's lower torso being more exposed to objects encountered while sledding. The injuries reported raise concerns about the safety of modern sleds and the possibility that design changes are needed.

Adolescent↗

Factors influencing the precision of estimating the postmortem interval using the triple-exponential formulae (TEF). Part I. A study of the effect of body variables and covering of the torso on the postmortem brain, liver and rectal cooling rates in 117 forensic cases.

Brain, liver, rectal and environmental temperatures were continuously monitored under controlled conditions, in 117 forensic fatalities, for up to 60 h after death. Cases were studied either naked (63%) or covered with two blankets (37%). Bodies were classified into fat and thin groups. Statistical analysis and curve-fitting of the data yielded the average triple-exponential formulae for each body site and each body group. The effects of covering of the torso and body parameters such as weight, height, surface area and 'cooling size factor' (Z) on postmortem cooling are assessed and discussed. Results show that covering of the torso has a significant influence on the rate of postmortem cooling, however, there is no good correlation between the body variables and the cooling rate.

Aged↗

[Establishment and discretization of human torso computer images for ECG simulation].

The establishment and discretization of human torso computer image is an important aspect in studying of ECG simulation. A rapid and effective method is presented in this paper, which establishes and discretes image of human torso exactly by curve fitting and by introducing concept of "nihility point". It also has some value for solving problem of discreting field region in numerical calculation of electromagnetic field.

Algorithms↗

A sensorized human torso phantom.

Force-torque measuring input devices can significantly enhance the performance of classical simulation environments that are, for example, based on pure passive phantoms. Such devices allow not only the determination of force/torque amplitude and direction but also the contact point on the phantom. The force/torque information can be displayed visually or acoustically, drive a realistic graphical animation environment or it can be saved and compared with a haptic library comprising the force/torque history of any medical specialist. In this paper the technical principle is exemplified by an interactive human torso. A plastic phantom model of a human torso is instrumented with a 6-degree-of-freedom force/torque sensor, thus, allowing an intuitive and interactive use for education of human anatomy.

Humans↗

Evaluation of torso shape and asymmetry associated with scoliosis.

This paper presents a technique for evaluating torso shape and asymmetry in scoliosis using indices of point-set data obtained from torso surface scans. Point-set data are the maximum curvature points of a surface scan and contain key shape information. The centroids, distributions and densities of point-set data are indices of shape and asymmetry. The mean-squared deviations of the centroids per-cross-section from the medial plane are indicative of asymmetry. The distribution and density of point-set data are indicative of shape. Evaluations using point-set data indices were 100% in accord with those based on the cosmetic score. Indices of point-set data have more degrees of freedom and were able to distinguish between scans that have similar cosmetic scores.

Adolescent↗

Inadequate granulopoiesis after major torso trauma: a hematopoietic regulatory paradox.

Late postinjury sepsis is largely the result of defective host defense including failure to maintain an adequate number of functioning phagocytic cells. In this study we used stem cell culture techniques to measure colony-stimulating activity and have quantitated the number of circulating myeloid stem cells to see if defects in granulopoiesis occur after major torso trauma. Forty-two acutely injured patients (13 blunt and 29 penetrating injuries; mean age, 29.7 years) undergoing laparotomy with an abdominal trauma index of 15 to 40 were studied prospectively. Blood samples were obtained on days 1, 5, and 10. Patients were segregated by injury severity: abdominal trauma index less than 25 (n = 25) versus abdominal trauma index greater than or equal to 25 (n = 17). The more severely injured (abdominal trauma index greater than or equal to 25) patients had fewer circulating granulocytes and monocytes. Colony-stimulating activity was below normal control levels in all patients and was decreased further with increased injury severity. The more severely injured patients had a blunted bone marrow response (significantly fewer circulating myeloid stem cells) and suffered more major septic complications (24% vs 8%). In conclusion, major trauma to the torso causes a paradoxic depression in granulopoiesis that worsens with increased injury severity and may contribute to late septic morbidity. This colony-stimulating activity deficiency state is similar to that seen after major burns and may be amenable to future modulation.

Abdominal Injuries↗