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 199 records · Page 11Linked to original sources
PubMed2006

Detection of lower torso ischemia by near-infrared spectroscopy during cardiopulmonary bypass in a 6.8-kg infant with complex aortic anatomy.

Neonates and small infants with congenital heart disease and complex cardiac and vascular anatomy are particularly prone to episodes of complete or incomplete regional ischemia during cardiopulmonary bypass. These episodes may result either from inhomogeneous distribution of arterial blood flow via the aortic cannula or from impaired drainage of blood via the venous cannulae. However, techniques for continuous routine monitoring of regional perfusion in neonates or small infants undergoing cardiopulmonary bypass are extremely limited. Over recent years, transcranial near-infrared spectroscopy has become established as a useful technique for the non-invasive monitoring of cerebral oxygenation. Here we present a case in which simultaneous near-infrared spectroscopic monitoring of the oxygenation status in the brain and the right upper thigh revealed lower torso ischemia due to accidental cross-clamping of a hypoplastic descending aorta which would otherwise have been unnoticed. This shows that parallel near-infrared spectroscopy of the brain and the lower extremities may represent a novel non-invasive monitoring technique to ensure adequate cerebral and extracerebral perfusion during cardiopulmonary bypass.

Aorta, Thoracic↗
PubMed2004

Admission lactate level and the APACHE II score are the most useful predictors of prognosis following torso trauma.

BACKGROUND: Markers of dysoxic metabolism and scoring systems for triage have been widely used in critically injured patients. However, so far, no model is sufficiently reliable to predict the outcome in trauma victims. The purposes of the present study, therefore, were to determine whether a correlation exits between the main trauma scoring systems and the markers of dysoxic metabolism. Moreover, to assess if any of the admission parameters can be used to indicate outcome. METHODS: Sixty-four patients were included in this study. Admission data, including arterial lactate level, base deficit (BD), pH, revised trauma score (RTS), injury severity score (ISS), shock index (SI), and Acute Physiology and Chronic Health Evaluation (APACHE II), were collected and analysed by logistic regression analysis. Degree of association between continuous variables were calculated by either Pearson's or Spearman's correlation coefficient, where applicable. The dependence of lactate on two or more other variables was evaluated by multiple linear regression analysis. RESULTS: Logistic regression analysis showed that the fatal outcome following major torso trauma was principally associated with the APACHE II score and lactate. The specificity and the sensitivity of this logistic regression model was 94.6 and 79.2%, respectively. According to standardised linear regression coefficients, BD was the best single predictor of lactate, and APACHE II added a small amount of predictive power. The proportion of total variation in lactate level explained by base deficit, APACHE II and age is R2=85.2%. CONCLUSION: APACHE II score and the arterial lactate level are the most important determinants of clinical outcome in critically injured patients. A correlation exits between lactate and APACHE II and between lactate and base deficit.

APACHE↗
PubMed2005

An operator splitting method for solving the bidomain equations coupled to a volume conductor model for the torso.

In this paper we present a numerical method for the bidomain model, which describes the electrical activity in the heart. The model consists of two partial differential equations (PDEs), which are coupled to systems of ordinary differential equations (ODEs) describing electrochemical reactions in the cardiac cells. Many applications require coupling these equations to a third PDE, describing the electrical fields in the torso surrounding the heart. The resulting system is challenging to solve numerically, because of its complexity and very strict resolution requirements in time and space. We propose a method based on operator splitting and a fully coupled discretization of the three PDEs. Numerical experiments show that for simple simulation cases and fine discretizations, the algorithm is second-order accurate in space and time.

Algorithms↗
PubMed2004

Sodium 3-D MRI of the human torso using a volume coil.

Sodium MR imaging is considered to provide clinically important information about the human body that is not achievable by hydrogen-based approaches. However, due to the low natural abundance in biological tissues, sodium signals usually lead to low spatial resolution, low SNR, and long acquisition times compared to conventional 1H imaging, even using well-adapted surface coils. For our study, a volume coil was designed with nearly homogeneous excitation/receive characteristics and a suitable geometry fitting the human torso. A sufficient penetration throughout the entire thorax, abdomen, or pelvis is provided allowing for sodium imaging of the kidneys, the liver with gall bladder, or the myocardium. All measurements were performed on a 1.5 T whole body scanner using a spoiled 3-D gradient echo sequence. Imaging parameters TE, TR, and readout bandwidth were optimized for sensitive recording of the sodium component with slow transverse relaxation. Nonselective RF excitation pulses with a duration of 2.5 ms and rectangular shape were applied to avoid SAR problems. Narrow receiver bandwidth and excitation near the Ernst angle provided clinically practicable examinations with measuring times of less than 15 min at a spatial resolution of 8 x 8 x 8 mm3. Under these conditions, SNR of 11 for the kidneys and vertebral disks, 9 for the spinal canal, and 6 for the liver was achieved. A special 3-D spin echo sequence was used to determine T2, times which resulted to 15.3 +/- 1.1 ms for liver, 27.7 +/- 7.2 ms for kidneys, and 24.0 +/- 4.7 ms for the content of the spinal canal.

Abdomen↗
PubMed2003

Principal components analysis as an evaluation and classification tool for lower torso sEMG data.

The use of univariate statistical techniques on multivariate electromyography data can fail to uncover important relationships between variables. Principal components analysis (PCA) is a multivariate statistical technique that can be used as a data exploration tool, both by classifying participants and simplifying data structures. Past research using this technique has focused on discriminating between "patients" and "normals". This investigation explored the use of PCA on electromyography data from healthy participants, with the objective of elucidating any between-participant differences in the multivariate patterns of muscle coactivation. Results indicated that, even between healthy participants, quantitative and qualitative differences in muscle coactivation patterns exist and that, in the context of the lower torso, a large portion (>70%) of the empirically determined muscle activation could be synthesized in a theoretical three-parameter control model.

Abdominal Muscles↗
PubMed1983

Effects of thoracotomy on volume conductor properties of the canine torso.

The effects of left thoracotomy on the volume conductor properties of the canine torso were studied in ten dogs. Body surface isopotential distributions were examined before and serially (3, 7 and 14-15 days) after limited thoracotomy and pericardiotomy. Changes in QRS potentials were considered to reflect surgically-induced alterations in volume conductor properties. Results demonstrated that thoracotomy caused a generalized reduction in body surface potentials, quantitated as root-mean-square errors that were greatest soon after surgery and reached low levels (less than 200 uV) two weeks postoperatively. Although voltages were reduced, overall isopotential distributions remained similiar in form, with statistically significant correlation coefficients (greater than 0.7) three days after surgery; these values increased to high (greater than 0.85), stable levels by one week. These findings help define the nature and time course of ECG changes that may be attributed to thoracotomy without direct cardiac intervention.

Animals↗
PubMed1999

Noninvasive visualization of multiple simultaneously activated regions on torso magnetocardiographic maps during ventricular depolarization.

The time course and instantaneous distribution of the electrophysiologic processes of the human heart were analyzed by using a multichannel superconducting quantum interference device (SQUID) system, enabling the tangential components of the cardiac magnetic fields to be measured. By visualizing the changing magnetic field pattern in a two-dimensional presentation of the anterior and posterior torso during depolarization, the existence of more than one simultaneously activated region and the effective intracardiac current distribution were estimated without using a mathematical algorithm. The mid-to-late QRS complex when the myocardium has widespread depolarizing regions was analyzed using this technique. Even in an early stage of the QRS, two discrete active regions were observed in the magnetic field maps, in all nine subjects (adults with normal hearts). Furthermore, differences in the current distribution between the front and back active region were observed.

Adult↗
PubMed1997

Hemodynamic effects of isovolemic hemodilution during descending thoracic aortic cross clamping and lower torso reperfusion.

BACKGROUND: Isovolemic hemodilution has been suggested for blood conservation and to improve hemodynamic tolerance to abdominal aortic cross clamping. However, the hemodynamic effects of hemodilution during descending thoracic aortic cross clamping (DAC) have not been established. We evaluated them in anesthetized swine. METHODS: Hemodilution (n = 7) was produced by the isovolemic exchange of blood for 6% hetastarch to a target hematocrit of 20%. Hematocrit in control pigs (n = 7) remained at 30%. DAC was performed at the T9 level for 45 minutes. During a 60-minute reperfusion period, control pigs were infused with lactated Ringer's solution; shed blood was returned to hemodilution pigs, followed by lactated Ringer's. If hypotension occurred despite left atrial pressure of 10 mm Hg or greater, boluses of phenylephrine were given to keep mean arterial pressure above 60 mm Hg. RESULTS: Hemodilution caused a marked reduction in hematocrit and in global oxygen delivery (DO2). DAC produced a significant increase in proximal arterial pressure, cardiac index, and DO2 and oxygen consumption (VO2) was markedly reduced in both groups. A significant increase in systemic vascular resistance during DAC occurred only in control pigs. After reperfusion, vascular resistance was significantly lower than baseline in hemodilution pigs, requiring a sixfold greater dose of phenylephrine to avoid hypotension. A lower global DO2 and supply-limited VO2 were also observed in hemodilution pigs. CONCLUSIONS: Isovolemic hemodilution maintains hemodynamic stability during DAC. During lower torso reperfusion, however, hemodilution caused hemodynamic instability, decreased global DO2, and limited VO2, which may offset its potential benefits.

Animals↗
PubMed2006

Differences in the sensations of cold on the anterior torso of control and spinal-cord-transected individuals.

Application of cold stimuli to the sentient portion of the anterior torso of 12 spinal-cord-transected individuals (patients) and to comparable sites of 11 control participants showed that thresholds are lower for women than for men and that the difference between the sexes is maintained following spinal-cord transection. Patients of both sexes were more sensitive to cold stimuli than were controls. Estimates of stimulus intensity showed that participants reliably distinguished the 3 cool stimuli but that control women offered significantly larger estimates than control men. Spinal-cord transection produced an increase in the intensity of the sensations in women and a reduction in men. The changes in sensory perception that follow spinal-cord injury extend throughout the somatosensory system and involve all modalities. These changes cannot be explained as a simple release from inhibition.

Analysis of Variance↗
PubMed1988

Function of torso in determining the terminal anlagen of the Drosophila embryo.

The formation of the unsegmented terminal regions of the Drosophila larva, acron and telson requires the function of at least five maternal genes (terminal genes class). In their absence, the telson and acron are not formed. One of them, torso (tor), has gain-of-function alleles which have an opposite phenotype to the lack-of-function (tor-) alleles: the segmented regions of the larval body, thorax and abdomen, are missing, whereas the acron is not affected and the telson is enlarged. In strong gain-of-function mutants, the pair-rule gene fushi tarazu (ftz) is not expressed, demonstrating the suppression of the segmentation process in an early stage of development. The tor gain-of-function effect is neutralized, and segmentation is restored in double mutants with the zygotic gene tailless (tll), which has a phenotype similar (but not identical) to that of tor-. This suggests that tor acts through tll, and that in the gain-of-function alleles of tor, the tll gene product is ectopically expressed at middle positions of the embryo, where it inhibits the expression of segmentation genes like ftz.

Animals↗
PubMed1989

Requirement of the Drosophila raf homologue for torso function.

In Drosophila the correct formation of the most anterior and posterior regions of the larva, acron and telson is dependent on the maternally expressed terminal class of genes. In their absence, the anterior head skeleton is truncated and all the structures posterior to the abdominal segment seven are not formed. The protein predicted to be encoded by one of these genes, torso (tor), seems to be a transmembrane protein with an extracytoplasmic domain acting as a receptor and a cytoplasmic domain containing tyrosine kinase activity. Here we report that another member of the terminal-genes class, l(1)polehole (l(1)ph), which is also zygotically expressed, is the Drosophila homologue of the v-raf oncogene and encodes a potential serine-and-threonine kinase. We also show that functional l(1)ph gene product is required for the expression of a gain-of-function tor mutant phenotype, indicating that l(1)ph acts downstream of tor. Together, these results support the idea that the induction of terminal development occurs through a signal transduction system, involving the local activation of the tor-encoded tyrosine kinase at the anterior and posterior egg poles, resulting in the phosphorylation of the l(1)ph gene product. In turn, downstream target proteins may be phosphorylated, ultimately leading to the regionalized expression of zygotic target genes. Such a process is in agreement with the finding that both tor and l(1)ph messenger RNAs are evenly distributed.

Animals↗
PubMed1990

The orthodenticle gene is regulated by bicoid and torso and specifies Drosophila head development.

In the Drosophila embryo, cell fate along the anterior-posterior axis is determined by maternally expressed genes. The activity of the bicoid (bcd) gene is required for the development of larval head and thoracic structures, and that of maternal torso (tor) for the development of the unsegmented region of the head (acron). In contrast to the case of thoracic and abdominal segmentation, the hierarchy of zygotically expressed genes controlling head development has not been clearly defined. The bcd protein, which is expressed in a gradient, activates zygotic expression of the gap gene hunchback (hb), but hb alone is not sufficient to specify head development. Driever et al. proposed that at least one other bcd-activated gene controls the development of head regions anterior to the hb domain. We report here that the homeobox gene orthodenticle (otd), which is involved in head development, could be such a gene. We also show that otd expression responds to the activity of the maternal tor gene at the anterior pole of the embryo.

Animals↗
PubMed1993

The torso receptor localizes as well as transduces the spatial signal specifying terminal body pattern in Drosophila.

Specification of the end portions of the Drosophila body depends on the torso (tor) protein, a receptor tyrosine kinase that accumulates uniformly along the entire surface of the embryo but is activated only in the vicinity of the poles. Several genes are normally required for activating tor and appear to define a system in which a gene product tethered to the extracellular vitelline membrane at each end of the egg provides a local source for an extracellular tor ligand. This ligand would have to diffuse from the membrane to the cell surface of the embryo without losing its spatial localization. Here we report that the failure to accumulate tor protein at one or both poles leads to spatially inappropriate activity of more centrally located receptor. This ectopic activity depends on the same gene functions normally required for activating tor; thus we infer that it reflects inappropriate diffusion of the ligand to more central regions of the body. We conclude that the receptor not only transduces the spatial signal imparted by the tor ligand, but also ensures its correct localization by sequestering the ligand. Ligand trapping by receptor may also localize spatial signals in other patterning systems, including specification of the dorsal-ventral axis in Drosophila and of vulval cell fates in Caenorhabditis elegans.

Animals↗
PubMed2000

Diaphragmatic dysfunction secondary to experimental lower torso ischaemia-reperfusion injury is attenuated by thermal preconditioning.

BACKGROUND: Preconditioning describes the process whereby tissue exposure to a subcritical stress confers protection from subsequent injuries. This study assessed diaphragmatic muscle function after lower torso ischaemia-reperfusion (IR) and the role of thermal preconditioning in attenuation of this injury. METHODS: Sprague-Dawley rats were randomized into three groups (24 per group): a control group, an IR group that had aortic cross-clamping for 1 h followed by reperfusion, and a third group that received thermal preconditioning 18 h before IR. Diaphragmatic function was assessed at 24 h, 48 h and 7 days. RESULTS: IR resulted in significant diaphragmatic twitch and tetanic dysfunction compared with control muscle. Thermal preconditioning significantly attenuated this injury (P < 0.05). Mean(s.e.m.) muscle twitch and tetanic forces in the IR group were 204.9(17.2) and 282.7(19.2) g respectively at 24 h. Corresponding twitch and tetanic forces in preconditioned muscle were 270.4(25.1) and 552.0(35.2) g. CONCLUSION: This study demonstrated that systemic IR injury produced a respiratory muscle mechanical dysfunction that was attenuated by thermal preconditioning, at 24 h, 48 h and 7 days. Preconditioning may have a role in clinical practice, particularly before elective surgery.

Animals↗
PubMed2001

Pravastatin attenuates lower torso ischaemia-reperfusion-induced lung injury by upregulating constitutive endothelial nitric oxide synthase.

OBJECTIVES: to elicit whether pre-treatment with pravastatin will prevent or ameliorate the acute lung injury that occurs following lower torso ischaemia-reperfusion (IR) in an experimental animal model. MATERIALS AND METHODS: male Sprague-Dawley rats were randomised into three groups (n=7/group). The control group underwent a sham laparotomy and aortic dissection. The second group underwent infrarenal aortic cross clamping for 30 min followed by reperfusion for 120 min. The third group pre-treated with pravastatin sodium (0.4 mg/kg/day over 5 days) were again subjected to an ischaemia-reperfusion (IR) injury. The parameters used to assess lung injury included: Wet to dry lung weight ratio (W:D), myeloperoxidase activity (MPO), protein concentration (BALprot) and neutrophil count (BAL PMN) of bronchoaveolar lavage fluid. Western blotting was used to determine the expression of constitutive endothelial nitric oxide synthase (ecNOS) within lung tissue. RESULTS: IR causes an acute lung injury as indicated by statistically significant differences in W:D lung weight ratios, MPO activity, neutrophil count and BALprotein concentration in the IR group over that of controls. Pre-treatment with pravastatin attenuated this neutrophil infiltration and microvascular leakage. The pravastatin group showed a marked increased expression of ecNOS over that of the IR group and controls. CONCLUSION: this data indicates that pre-treatment with pravastatin protects against ischaemia-reperfusion induced lung injury in an experimental animal model. We believe that its mechanism of action involves an upregulation of ecNOS, which increases basal expression of nitric oxide providing protective effects on the pulmonary circulation against microvascular injury.

Analysis of Variance↗
PubMed2002

A multiantioxidant supplementation reduces damage from ischaemia reperfusion in patients after lower torso ischaemia. A randomised trial.

BACKGROUND: open repair of intra-abdominal aortic aneurysm (AAA) is associated with lower torso ischaemia and reperfusion. OBJECTIVE: to examine the effect of antioxidants on the activation and sequestration of white blood cells and muscle injury during AAA repair. METHOD: forty-two patients undergoing elective infrarenal aneurysm repair, were randomised to either standard therapy (22 patients) or standard therapy with additional multiantioxidant supplementation (20 patients). Vitamin E and C, Allopurinol, N-acetylcysteine and mannitol was administered perioperatively. White blood cell count (WBC), serum creatine kinase, aspartateaminotransferase, lactate and lipofuscine were measured. RESULTS: WBC remained higher after reperfusion in the antioxidant group (p = 0.008). CK, ASAT and lipofuscine levels were significantly lower after reperfusion in the antioxidant group (p = 0.02, p = 0.018, p = 0.017). CONCLUSION: multi-antioxidant supplementation was associated with a reduction in serum CK and ASAT after AAA repair. This is likely due to a reduction in oxidative stress and a decreased leucocyte sequestration and activation.

Aged↗
PubMed2000

Effects of vestibular and cerebellar deficits on gaze and torso stability during ambulation.

We measured gaze, head, and torso stability during ambulation to determine how vestibulo-ocular reflex dysfunction caused by unilateral vestibulopathy, bilateral vestibulopathy, and cerebellar dysfunction might affect image stabilization on the retina. Subjects were tested during standing, walking, and running on a treadmill. Gaze velocity, vestibulo-ocular reflex gain, and head velocities were calculated from angular positions of the eye and head, as well as linear positions of the head and trunk. Mean gaze velocity with a visible, distant target was below 4 degrees /second for all measurement conditions in control and vestibulopathic subjects. The performance of unilaterally vestibulopathic subjects was indistinguishable from that of control subjects except that the former had less vertical translation during walking. Bilaterally vestibulopathic subjects demonstrated less head translation than control subjects but had higher gaze velocity. In subjects with cerebellar dysfunction, gaze velocity was elevated by pathologic nystagmus, but head movements were similar to those of control subjects.

Adult↗