Elevated serum CCL2 concomitant with a reduced mycobacterium-induced response leads to disease dissemination in leprosy

Mycobacterium leprae and Mycobacterium tuberculosis are successful intracellular pathogens which down regulate host immune responses. T-cell interferon-gamma (IFNgamma) and macrophage tumour necrosis factor-alpha (TNFalpha) activate chemokines such as, C-C chemokine ligand-2 (CCL2) and CCL5, which play a role in granuloma formation. Lepromatous leprosy is characterized by defective granulomas with lowered T-cell- and macrophage-mediated responses. Tuberculosis (TB) can be localized to the lung, whereby discreet granulomas are formed. The role of chemokines in leprosy infections is as yet unclear. We compared chemokine responses in lepromatous leprosy and pulmonary tuberculosis patients. Circulating serum CCL2 was raised while CCL5 was lowered in leprosy, as compared with TB patients and healthy controls. However, both Mycobacterium bovis BCG- (P=0.08) and M. leprae-induced (P=0.05) CCL2 secretion was reduced in leprosy. In leprosy, BCG induced greater CCL2 (P=0.01), TNFalpha (P=0.02) and somewhat greater CCL5 (P=0.08) than M. leprae, while CXCL8 induction was comparable. Overall levels of Mycobacterium-induced CCL2, TNFalpha and CXCL8 were two to threefold lower, and CCL5 was 10-fold lower in leprosy as compared with TB. Reduced inducible CCL2 combined with a lowered TNFalpha response in lepromatous leprosy may contribute to the unrestricted growth and dissemination of mycobacteria found in the disease.

The Human Motor Control System's Response to Mechanical Perturbation: Should It, Can It and Does It Ensure Stability?

From among the diverse meanings of stability, the one the author adopts here is that the effects of a perturbation are opposed, and therefore small effects remain small. Except in linear systems, however, instability need not lead to unbounded motion and may actually be desirable when maneuverability is important. Moreover, properties of nerves, muscles, and tendons present serious challenges to stabilization. A review of observations from the motor control literature reveals that responses to perturbations in many common situations assist rather than resist the perturbation and are therefore presumably destabilizing. The observations encompass situations of position maintenance as well as impending or ongoing movement. The author proposes that the motor control system responds to a sudden perturbation by a pattern of muscle activity that mimics an accustomed voluntary movement, oblivious of stability considerations. What prevents runaway motion in the face of short-term instability appears to be voluntary intervention.

A laboratory method for purification of major cow's milk allergens

Food allergy is responsible for the most frequent allergic reactions in children under 1 year of age. Diagnostic tests such as skin test or specific IgE assay usually need highly purified preparations of allergenic proteins. The aim of the present study was to purify three main cow's milk proteins: casein, alpha-lactalbumin, and beta-lactoglobulin as allergenic extracts for first time in Iran.

Leprosy patients with lepromatous disease have an up-regulated IL-8 response that is unlinked to TNF-alpha responses

Tumor necrosis factor (TNF-alpha) in conjunction with interferon-gamma (IFN-gamma) plays an important role in lymphocyte recruitment and granuloma formation in mycobacterial diseases. Lepromatous leprosy infections are typically associated with low to absent T cell responses and the absence of INF-gamma secretion. Chemokines such as IL-8, MCP-1, and MIP-1beta, have also been shown to recruit neutrophils and lymphocytes to the site of mycobacterial infections. We have studied IL-8 expression in relation to TNF-alpha and TGF-beta in monocytes from lepromatous patients (LL) as compared with healthy endemic controls. In endemic controls, no spontaneous expression of IL-8, TNF-alpha, and TGF-beta was observed, but BCG and M. leprae induced activation of all three cytokines. Lepromatous leprosy monocytes spontaneously expressed high levels of IL-8 and TGF-beta but negligible levels of TNF-alpha. A further increase in IL-8 secretion or gene expression by BCG or M. leprae was not significant. BCG, but not M. leprae, was able to stimulate TNF-alpha activation in lepromatous leprosy subjects. TGF-beta responses in LL were parallel to those of IL-8. This suggests a vigorous and active ongoing IL-8 response in lepromatous disease that is independent of TNF-alpha activation. Therefore, in the absence of IFN-gamma and TNF-alpha activation, IL-8 may assume a pivotal role in cell recruitment in leprosy patients with disseminated mycobacterial infections.

IgG1 antimycobacterial antibodies can reverse the inhibitory effect of pentoxifylline on tumour necrosis factor alpha (TNF-alpha) secreted by mycobacterial antigen-stimulated adherent cells

Chronic inflammation associated with cachexia, weight loss, fever and arthralgia is the hallmark of advanced mycobacterial diseases. These symptoms are attributed to the chronic stimulation of tumour necrosis factor (TNF)-alpha. Mycobacterial components directly stimulate adherent cells to secrete TNF-alpha. We have shown recently that IgG1 antimycobacterial antibodies play a role in augmenting TNF-alpha in purified protein derivative (PPD)-stimulated adherent cells from non-BCG-vaccinated donors. We now show that IgG1 antibodies can also augment TNF-alpha expression in stimulated adherent cells obtained from BCG-vaccinated donors and this augmentation is not linked to interleukin (IL)-10 secretion. In addition IgG1 antimycobacterial antibodies can reverse the effect of TNF-alpha blockers such as pentoxifylline and thalidomide. These studies therefore have clinical implications for anti-inflammatory drug treatments which are used increasingly to alleviate symptoms associated with chronic inflammation.

The effect of mycobacterial virulence and viability on MAP kinase signalling and TNF alpha production by human monocytes

SETTING

The success of Mycobacterium tuberculosis as a human pathogen depends on its ability to tolerate and perhaps manipulate host defense mechanisms.

OBJECTIVE

To determine the induction of tumour necrosis factor-alpha (TNF alpha), a central mediator of immunity, by human monocytes infected with virulent M. tuberculosis, M. leprae and attenuated M. bovis BCG.

DESIGN

Mycobacteria-induced cellular activation pathways of TNF alpha production was investigated using an inhibitor of protein tyrosine kinase (PTKs) and an inhibitor of mitogen-activated protein (MAP) kinases.

RESULTS

TNF alpha production was significantly lower during infection with virulent M. tuberculosis than with BCG and this differential response was independent of mycobacterial viability. TNF alpha production involved the PTK and MAP kinase pathways. Reduced TNF alpha induction by M. tuberculosis was associated with a reduction in the extent and duration of phosphorylation of extracellular-signal regulated kinases (ERK 1/2). Infection with M. leprae triggered low and transient ERK 1/2 activation as well as low TNF alpha production.

CONCLUSION

Maintenance of the differential response in both live and heat-killed preparations suggests that the reduced TNF alpha response associated with virulent mycobacteria is due to differences in the presence of components capable of triggering host pattern recognition receptors, rather than events associated with phagosome trafficking or the active release of intracellular modulators.

Trajectories of target reaching arm movements in individuals with spinal cord injury: effect of external trunk support

DESIGN

Deficits in trunk control due to spinal cord injury (SCI) lead to slower target-reaching movements of the hand. We investigated whether the movement path is also affected, and whether providing external support for the trunk can abolish the kinematic differences.

OBJECTIVE

To compare movement trajectories between individuals with SCI and neurologically normal individuals, with and without external trunk support.

SETTING

Neural Control/Biomechanics Laboratory, University of Illinois, Chicago, USA.

METHODS

Five subjects with levels of injury between C7 and T4 were tested 3-8 years post-injury, and compared with five control subjects. Two targets were employed. Trajectories were recorded by a motion-capture system using infrared emitting markers. Peak speed and path curvature were calculated for the fingertip and for the acromion.

RESULTS

Compared with control subjects, the subjects with SCI exhibited lower peak speed of the fingertip but not of the acromion, and less straight paths for both. When the trunk was supported externally, the difference in fingertip speed persisted. The support abolished the difference in path curvature for the fingertip but accentuated that for the acromion.

CONCLUSION

The slower hand movements of individuals with SCI are not simply time-scaled versions of those of normal subjects, and the provision of trunk support does not erase the kinematic differences between the reaching movements of the two groups.

Horizontal-plane arm movements with direction reversals performed by normal individuals and individuals with down syndrome

We examined the systematic variation in shoulder and elbow torque, as well as movement kinematics, for horizontal-plane arm movements with direction reversals performed by normal individuals and individuals with Down syndrome. Eight neurologically normal individuals and eight individuals with Down syndrome performed horizontal, planar reversal movements to four different target locations. The four locations of the targets were chosen such that there is a systematic increase in elbow interaction torque for each of the four different target locations. This systematic increase in interaction torque has previously been shown to lead to progressively larger movement reversal errors, and trajectories that do not show a sharp reversal of direction, for movements to and from the target in patients who have proprioceptive abnormalities. We computed joint torques at the elbow and shoulder and found a high correlation between elbow and shoulder torque for the neurologically normal subjects. The ratio of joint torques varied systematically with target location. These findings extend previously reported findings of a linear synergy between shoulder and elbow joints for a variety of point-to-point movements. There was also a correlation between elbow and shoulder torque in individuals with Down syndrome, but the magnitude of the correlation was less. The ratio of joint torques changed systematically with target direction in individuals with Down syndrome but was slightly different from the ratio observed for neurologically normal individuals. The difference in the ratio was caused by the generation of proportionately more elbow torque than shoulder torque. The fingertip path of individuals with Down syndrome showed a sharp reversal in moving toward and then away from the target. In this respect, they were similar to neurologically normal individuals but dissimilar to individuals with proprioceptive deficits. Finally, we observed that individuals with Down syndrome spend proportionately more time in the vicinity of the target than normal individuals. Collectively these results show that there is a systematic relationship between joint torques at the elbow and shoulder. This relationship is present for reversal movements and is also present in individuals with Down syndrome.

Are the elderly in Pakistan getting their due share in health services? Results from a survey done in the peri-urban communities of Karachi

OBJECTIVE

To assess the health, activity and social status of the elderly.

METHODS

This Cross-sectional study with qualitative and quantitative designs was conducted in two areas of Karachi; one was a peri-urban squatter settlement and other a middle income community. The students of second year at Jinnah Medical College were trained to collect data, which was then entered on database IV and analyzed on the SPSS statistical package.

RESULTS

The average age of peri-urban respondents was 66 and urban was 69 years. Majority of the senior citizens were independent and 69% had active daily life (ADL), power of decision making for adults was related to their status in the family (p < 0.000), majority were alert, happy and satisfied with life with no difference between urban and peri-urban residents. Fifty-three percent of peri-urban and 25% of the urban residents wanted to be employed and 13% of peri-urban and 22% of the urban wanted to continue working at the time of retirement. Fifty-two percent were suffering from hypertension and out of these 81% were on medication and of these 33% could not take drugs due to economic reasons. Their ailments included diabetes (15.6%), difficulty in walking (46.7%), vision disturbances (71.3%) and hearing loss. Seventy-three percent said that the health care services are present, but insufficient to deal with geriatric care (50%) and unsatisfactory (53%). There was a total lack of social services for elderly in the community.

CONCLUSION

In the present cultural set up of Pakistan although the elderly are taken care of by their families but the majority want to continue working and be more independent. Most of the study population had one or the other form of ailment related to ageing which impaired their ADL indicator. There is extreme deficiency of health and social care services for the elderly hence the health care providers should start allocating and improvising for the specialized needs of the elderly. The social structure for elderly should be developed and jobs should also be created for the ones willing to continue working.

Electromyographic responses to a mechanical perturbation applied during impending arm movements in different directions: one-joint and two-joint conditions

Directional tuning is a common finding for many physiological features of arm movements and related neuronal activity. We investigated whether the electromyographic response to a brief (30 ms) torque perturbation prior to voluntary movement depends on the direction of the impending movement. Pointing movements with the elbow joint alone and those involving both the shoulder and elbow joints were studied in separate experiments. Target direction was varied between flexion and extension for the one-joint experiments and among four spatial directions for the two-joint experiments. Movement trials in which a perturbation stretched the flexor muscles just prior to the pointing movement were randomly interspersed among unperturbed movement trials in each experiment. A small pre-load ensured some background activity of the flexor muscles. Results were remarkably similar for the one- and two-joint conditions. The short-latency reflex response of the stretched muscles (in a 30-60 ms window after perturbation onset) was not modulated with direction of target-reaching movement in a statistically significant manner, which confirms earlier findings for one-joint movements and extends these to the two-joint condition. Beyond the short-latency window, the perturbation provoked earlier onsets of target-reaching muscle activities for the agonist muscles, whether or not the muscle had been stretched by the perturbation. The onset of the braking activity of the antagonist muscles also occurred earlier in the presence of the brief perturbation prior to movement, irrespective of whether the muscle had been stretched or not. The magnitude of target-reaching muscle activity, in general, was greater for the perturbed trials, though not consistently for all muscles or all directions. These results suggest that, when movement is about to be initiated, in either single- or multi-joint conditions, the long-latency effects of the stretch strongly depend on the intended direction of movement. The dependence is such that the response serves to hasten and augment the intended movement, but not necessarily to oppose the perturbation.

Assessment of immunity to mycobacterial infection with luciferase reporter constructs

Protective immunity to mycobacterial infection is incompletely understood but probably involves the coordinated interaction of multiple cell types and cytokines. With the aim of developing assays that might provide a surrogate measure of protective immunity, we have investigated the use of recombinant mycobacteria carrying luciferase reporter enzymes to assess the effectiveness of antimycobacterial immunity in model systems. Measurement of luminescence was shown to provide a rapid and simple alternative to the counting of CFU as a means of monitoring mycobacterial viability. We describe optimization of a luciferase reporter strain of Mycobacterium tuberculosis and demonstrate its application for the study of mycobacterial interactions with host cells in tissue culture and the rapid assessment of vaccine efficacy in a murine model.

Competitive polymerase chain reaction for the determination of N-myc amplification in neuroblastoma: report of clinical cases

If an unfavorable prognosis is suspected in neuroblastoma, decision on a treatment protocol should be based on the N-myc copy number (12). We already demonstrated that the newly developed competitive polymerase chain reaction (competitive PCR) is a promising method for the determination of the N-myc copy number (6), and have started to use this competitive PCR procedure in neuroblastoma patients, together with fine-needle biopsy in selected cases. Seven children were studied. In one infant of 5 months of age whose tumor was diagnosed before undergoing mass screening for neuroblastoma, the competitive PCR procedure was performed with a fine-needle biopsy, and after obtaining a negative report on N-myc amplification within 48 hours, a regular protocol of treatment could be started without delay. We report that competitive PCR is a rapid and accurate method for the determination of the N-myc copy number, requiring only a small amount of material, and anticipate that competitive PCR will become the procedure of choice for the determination of N-myc copy number in neuroblastoma.

The spinal curve in standing and sitting postures in children with idiopathic scoliosis

STUDY DESIGN

A sample of convenience of children with moderate idiopathic scoliosis without bracing or surgery was studied. The sample consisted of 19 children, aged 9 to 16 years, with mean Cobb angle of 24 degrees. The spinal configurations and paraspinal muscle activity in several commonly assumed postures were examined.

OBJECTIVES

To determine how the apex angles, verticality of spine, and muscle activity vary with the assumed posture and whether the location and the number of spinal curves affect these variables.

SUMMARY OF BACKGROUND DATA

It has been suggested that the configuration of the spine in commonly assumed postures can affect the spinal curve in scoliosis because of gravitational bending moments. There is, however, a paucity of data obtained in subjects in sitting postures that school-age children assume daily for prolonged periods. Absence of bilateral symmetry in pressure during sitting has been described, but its effect on the spinal apex angle has not been investigated.

METHODS

Infrared-emitting markers, whose three-dimensional positions could be tracked by a pair of cameras, were affixed to the spine. The natural postures studied were relaxed standing, relaxed sitting, erect sitting, and writing while seated. Electromyographic activity in muscles close to the spinal apexes was recorded bilaterally for each test posture.

RESULTS

Subjects leaned laterally and, in general, anteriorly, in all test postures, rather than placing the C7 vertebra vertically above S1. The direction of lean and the change in the spinal apex angle from standing to sitting varied depending on whether the spinal curve was single or double, thoracic or lumbar. Subjects with single curves, whether thoracic or lumbar, tended to lean laterally toward the convexity of their curve apex--that is, the lean was in a direction that reduced the apex angle. Subjects with double curves (thoracic and lumbar), in all postures except relaxed sitting, tended to lean toward the convexity of the lumbar curve, thereby reducing the lumbar apex angle and exacerbating the thoracic angle. Most subjects' apex angles were smaller in relaxed or erect sitting than in relaxed standing. Electromyographic activity was in general greater on the convex side of the curve, with greatest activity in erect sitting.

CONCLUSIONS

The findings indicate that in self-selected postures the gravitational effect of leaning and the muscle activity in paraspinal muscles may serve to reduce the apex angle. Thus, a fully upright, centered posture may not be best for correction of every patient's spinal curve.

Subcellular fractionation by organelle electrophoresis: separation of phagosomes containing heat-killed yeast particles

Uptake of foreign material and its subsequent lysosomal degradation is an important function of macrophages. The mechanisms involved in the binding, uptake and delivery of such material to lysosomal organelles, are, however, poorly understood. Here we describe a method using organelle electrophoresis to study the uptake and trafficking of heat-killed yeast particles within murine macrophages. Such yeast particles, which were fluorescently labeled, could be readily detected in intact cells as well as in subcellular fractions. Organelle electrophoresis of a homogenate from macrophages that had internalized yeast particles resulted in the separation of yeast-containing organelles from most other subcellular membranes. In addition, this method was used to follow the kinetics of yeast particle transport within macrophages could be followed readily. Organelle electrophoresis may be a valuable tool for the analysis of phagocytosis.

A study of the specificity of barley chymotrypsin inhibitor 2 by cysteine engineering of the P1 residue

A combination of oligonucleotide-directed mutagenesis and chemical modification was used to produce reactive site (P1) variants of chymotrypsin inhibitor II (CI2) in an attempt to create more potent inhibitors and examine inhibitory specificity. Mutagenesis to introduce a unique cysteine (CI2M59C) followed by modification to S-carboxamidocysteine with iodoacetamide produced a 7-fold more potent inhibitor of subtilisin BPN' than the wild type inhibitor. Modification with iodoacetic acid, which gives a negatively charged P1 residue (S-carboxymethylcysteine), generates a weaker inhibitor of subtilisin BPN' and chymotrypsin. Further chemical modification experiments of CI2M59C with a series of iodoalkanes of increasing chain lengths was used to determine the optimal P1 side chain length required for potent inhibition of porcine pancreatic elastase. A trend was observed which implies that for CI2 the original methionine residue or its isostere S-ethylcysteine are most effective residues at this position and not alanine as might have been expected from the substrate specificity. The mutant CI2M59C did not inhibit human neutrophil elastase. The iodoalkane modifications not only resulted in recovery of inhibitory activity but also proved to be substantially more potent inhibitors of human neutrophil elastase than wild-type CI2.

Pentylenetetrazol seizure threshold in the rat during recovery phase from propofol and thiopentone induced anesthesia

Pentylenetetrazol (PTZ) seizure threshold was determined in the rat during recovery from anesthesia induced by intravenous administration of propofol (20 mg/kg) or thiopentone (30 mg/kg). Seizure threshold values determined 10 min after the induction of anesthesia by either agents were significantly higher than those determined in control animals, indicating an anticonvulsant effect. With propofol, the initial rise in PTZ convulsive threshold declined rapidly during recovery from anesthesia and returned to control levels 40 min after drug administration. With thiopentone, the initial rise in convulsive threshold also declined during recovery phase but did not return to control levels at 90 min after drug administration. At no time during or after recovery from anesthesia induced by either anesthetic agents, did the PTZ conclusive threshold fall below control values. Thus, using the PTZ convulsive threshold, no proconvulsant effects were detected during the early phase of recovery from propofol or thiopentone induced anesthesia.

Isolation and characterization of the mycobacterial phagosome: segregation from the endosomal/lysosomal pathway

Mycobacteria have the ability to persist within host phagocytes, and their success as intracellular pathogens is thought to be related to the ability to modify their intracellular environment. After entry into phagocytes, mycobacteria-containing phagosomes acquire markers for the endosomal pathway, but do not fuse with lysosomes. The molecular machinery that is involved in the entry and survival of mycobacteria in host cells is poorly characterized. Here we describe the use of organelle electrophoresis to study the uptake of Mycobacterium bovis bacille Calmette Guerin (BCG) into murine macrophages. We demonstrate that live, but not dead, mycobacteria occupy a phagosome that can be physically separated from endosomal/lysosomal compartments. Biochemical analysis of purified mycobacterial phagosomes revealed the absence of endosomal/lysosomal markers LAMP-1 and beta-hexosaminidase. Combining subcellular fractionation with two-dimensional gel electrophoresis, we found that a set of host proteins was present in phagosomes that were absent from endosomal/lysosomal compartments. The residence of mycobacteria in compartments outside the endosomal/lysosomal system may explain their persistence inside host cells and their sequestration from immune recognition. Furthermore, the approach described here may contribute to an improved understanding of the molecular mechanisms that determine the intracellular fate of mycobacteria during infection.

Exercise at low altitude (Jordan Valley) causes changes in serum levels of ACTH, insulin, cortisol and lactate

This study was designed to examine the effects of exercise on adrenocorticotropic hormone (ACTH) and cortisol at low altitude (350 meters below sea level) and to compare these effects with those at a moderate level altitude (620 meters above sea level). Ten male trained athletes participated in a 21-K(m) non-competitive race. Serum levels of ACTH, luteinizing hormone (LH), growth hormone and cortisol were measured before and after the race at each of the altitudes. A significant increase in serum levels of ACTH was observed in response to this exercise only at low altitude. Serum levels of growth hormone were increased at both altitudes. Those of LH were not affected. Serum cortisol levels were increased following exercise at both altitudes. It is proposed here that ACTH may play a role in acclimatization to exercise at low altitudes. The role of growth hormone and LH in this conditioning process seems to be insignificant. Additionally, serum levels of insulin and lactate were also measured in these experiments. Exercise caused a decrease in serum insulin levels at both altitudes. Serum levels of lactate were decreased only at low altitude. These changes of serum levels of insulin and lactate suggest a type of metabolic adjustment to meet energy requirements. Changes in energy metabolism can be correlated by changes in the ratio of insulin to serum cortisol levels and those of other counter-regulatory hormones in response to exercise at both altitudes.

Acute effects of exercise at low altitude (350 meters below sea level) on hormones of the anterior pituitary & cortisol in athletes

The purpose of this study was to examine the effects of exercise on anterior pituitary hormones (adrenocorticotropic hormone (ACTH), leutinizing hormone (LH) and growth hormone) as well as on cortisol at low altitude (350 meters below the sea level) and to compare these effects with those at a moderate level altitude (620 meters above the sea level). Ten male athletes with running experience participated in a 21-Km competitive race. Serum levels of ACTH, LH, growth hormone and cortisol were measured before and after the race at each of the altitudes. A significant increase in the serum levels of ACTH and growth hormone were observed in response to this exercise at low altitude. Similar exercise at 620 meters above the sea level resulted in a significant increase only in the serum levels of growth hormone. Serum levels of LH were not affected by this kind of exercise at both altitudes. Serum cortisol levels were increased following exercise at both altitudes. Altogether, these observations show a differential response of the anterior pituitary to exercise at low and normal altitudes. These data suggest that ACTH may have a role in the acclimatization to exercise at low altitudes. The role of growth hormone and LH in this conditioning process seems to be insignificant. The changes in serum cortisol levels in response to exercise at both altitudes correlate well with the effect of exercise on energy metabolism.

Competitive polymerase chain reaction for the quantification of N-myc gene copy number in neuroblastoma

An absolute quantification method for the N-myc gene copy number of neuroblastoma specimens was established by applying the competitive polymerase chain reaction (cPCR). The competitor plasmid (pZH2) lacking an MluI site in the exon 2 was constructed to distinguish two product species amplified from genomic DNA and the competitor plasmid. By using this cPCR system, we could obtain qualitative results within 1 day, i.e. amplified or unamplified, and quantitative results by using radiolabelled nucleotides within 4 days. The copy numbers of N-myc in 47 neuroblastoma specimens by cPCR correlated well with those by Southern hybridization (r = 0.85). We conclude that cPCR is a simple and rapid method, requires only a small amount (200 ng) of sample DNA, and is expected to be used for prognostic evaluation in neuroblastomas.

Qualitative discrepancies between trunk muscle activity and dynamic postural requirements at the initiation of reaching movements performed while sitting

Reaching movements are associated with widespread, nonfocal muscle activity. That activity is often assumed to play a postural role. We tested this assumption for the trunk muscles at the initiation of reaching movements with the following question. Does initial trunk muscle activity play a dynamic postural role by resisting the segmental interactive effects of the arm movement on the trunk? Seated subjects performed bilateral reaching movements while target direction was systematically varied. Muscle activity was recorded from flexors and extensors of the trunk and shoulder. Trunk muscle activity was compared with trunk torques calculated from simulations of reaching movements in which the trunk was modeled to stay still. Recorded trunk muscle activity was in qualitative agreement with torque predictions for only some target directions, suggesting that the target directions to counteract postural disturbances at the initiation of reaching movements.