Kinematics of the wrist using 2D and 3D analysis: biomechanical and clinical deductions.

Surgery of the wrist relies on the known notions of biomechanics of the wrist. But these notions are incomplete. For a better understanding of the movements of the wrist, we studied five wrists of healthy volunteers with CT scanning. Each wrist was studied in neutral position, and in the four extreme positions: flexion, extension, radial and ulnar deviations. Using oblique reformatted CT sections, we measured the angular displacements in frontal and sagittal views of every carpal bone in the different positions of the wrist. This allowed us to construct a table of intracarpal mobility. By comparing the angle values and the three-dimensional pictures of these wrists, we illustrate some fundamental points regarding intracarpal movement. The dynamics of the wrist are like those of two super-imposed mobile cups with different movements. The proximal row is malleable with flattening and torsion according to the transverse axis and its behavior is like that of an articular meniscus. The distal row, more rigid but deformable, behaves like a T-handle giving attachment to the hand and articulating under the proximal row around the head of the capitate and the proximal pole of the hamate. During radial and ulnar deviations of the wrist, the movement between the two rows is like an inverse pronation-supination shearing. During flexion-extension, the distortion of the two rows allows maximal congruence to be maintained between the different carpal bones.

[Shoulder fusion for sequelae secondary to brachial plexus palsy]. / Arthrodèse d'épaule pour séquelles de paralysies du plexus brachial.

PURPOSE OF THE STUDY: We examined clinical and radiological outcome in fifteen patients who underwent shoulder fusion after brachial plexus palsy. MATERIAL AND METHODS: This retrospective analysis included 15 patients who underwent shoulder fusion between 1981 and 1997 for the treatment of sequelae secondary to brachial plexus palsy. There were 13 men and two women, mean age 24.6 years (range 18-33 years). The right shoulder was fused in nine cases and the dominant shoulder in ten. There was one obstetric paralysis and one paralysis secondary to a cervical neurinoma. Eleven patients were motorcycle accident victims and two were automobile accident victims. The patients were installed in the lateral supine position with 30 degrees antepulsion and 60 degrees abduction, measured from the axillary axis of the scapula, and internal rotation. All patients had internal fixation by plate through a posterior approach. The same observer examined all the patients at last follow-up. Clinical and radiological findings were recorded and the position of the arthodesis was analyzed. RESULTS: There was one case of delaved fusion and one case of late humeral fracture. The arthrodesis position was abduction 52 degrees, internal rotation 20 degrees, flexion 20 degrees (means). Hand-mouth and hand-pocket movements were possible for all patients. Seven had no pain. Active motion was: 48 degrees abduction, 46 degrees antepulsion, 40 degrees internal rotation, 4.6 degrees external rotation, 23 degrees retropulsion. For 13 patients, mean lifting force was 5.2 kg.

[Anuerysm of the ulnar artery in a mountain biker. A case report and review of the literature]. / Anévrisme de l'artère ulnaire chez le cycliste tout terrain. A propos d'un cas clinique et revue de la littérature.

A case of ulnar artery aneurysm following repeated hand injury in a mountain biker, is reported. The patient underwent surgical aneurysm resection with venous graft end-to-end anastomosis. Complete relief of symptoms is observed at 3 years follow-up. A literature review is presented.

[Reconstruction of the distal radius for primary bone tumors using a non-vascularized fibular graft (report of 4 cases)]. / Reconstruction du radius par greffon fibulaire non vascularisé pour tumeur osseuse primitive (à propos de quatre cas).

We report four cases of primary bone tumour of the distal radius. Follow-up averaged ten years with a range of four to 13. Each case underwent excision of the tumour followed by reconstruction with a non-vascularised fibular graft. The aim of our study was to investigate the carcinologic, functional and radiological results at an average of ten years after the initial surgery. There were three high grade osteosarcomas and one giant cell tumour of bone. The mean postoperative wrist flexion was 45 degrees, extension was 20 degrees, pronation 30 degrees and supination 50 degrees. Radial tilt was a mean 10 degrees and ulnar tilt 15 degrees. All the patients had satisfactory function so as to be able to perform activities of daily living and to work. Grip strength was normal in three cases and reduced in one. Bone graft healing occurred at a mean of six months with a range of from four to nine months. Resection followed by a non-vascularised fibular graft is an effective way to managing these patients.

[Atypical Fenton syndrome]. / Syndrome de Fenton atypique.

The case of a patient 41 years old is reported. He sustained a posterior open carpal fracture dislocation transcapho-trans-capitate with radius styloid process fracture. The original aspect of this observation is that the lunatum was enucleated. The treatment was not usual. Capitatum bone was first fixed and associated with an external fixation. Proximal row carpectomy was performed in a second procedure when removing internal and external fixation, capitatum being healed. Follow up is now at four years with a very good radiological and clinical result. The patient is working with an intermittent mild pain. Radiographic examination demonstrated a very good vascularisation of the capitate head.

Bone gains and losses follow seasonal training and detraining in gymnasts.

The response of the human skeleton to high magnitude loading and unloading is poorly understood. Our aim was to evaluate changes in bone mineral density (BMD) in a group of intercollegiate gymnasts (n = 8, age = 18.6+/-0.8 years) over 24 months that included two 8-month competitive seasons and two 4-month offseasons. BMD of the hip, spine, and whole body was evaluated by DXA (Hologic QDR-1000/W) at baseline, 8, 12, 20, and 24 months. Results indicated significant seasonal trends in BMD of the femoral neck, trochanter, total hip, lumbar spine, and whole body. Specifically, there was a strikingly consistent pattern of bone density increases over the training seasons followed by clear declines in the offseasons. Increases at the spine were 3.5% and 3.7% followed by declines of 1.5% and 1.3% in the offseasons. Total hip BMD increased 2.3% and 1.9% during the competitive seasons followed by decreases of 1.5% and 1.2% in the offseasons. We observed a significant 24-month increase of 4.3% in spine BMD but no significant overall change at the hip. In conclusion, the human skeleton demonstrated a measurable response to high magnitude loading and unloading that was consistent across bone sites over 24 months of observation.

Arsenic alters the function of the glucocorticoid receptor as a transcription factor.

Chronic human exposure to nonovertly toxic doses of arsenic is associated with an increased risk of cancer. Although its carcinogenic mechanism is still unknown, arsenic does not directly cause DNA damage or mutations and is therefore thought to act principally as a co-mutagen, co-carcinogen, and/or tumor promoter. Previous studies in our laboratory demonstrated that effects of low-dose arsenic (III) (arsenite) on expression of the hormone-regulated phosphoenolpyruvate carboxykinase (PEPCK) gene were strongly associated with the glucocorticoid receptor (GR)-mediated regulatory pathway. We therefore examined specifically the effects of arsenite on the biochemical function of GR in hormone-responsive H4IIE rat hepatoma cells. Completely noncytotoxic arsenite treatments (0.3-3.3 microM) significantly decreased dexamethasone-induced expression of transiently transfected luciferase constructs containing either an intact hormone-responsive promoter from the mammalian PEPCK gene or two tandem glucocorticoid response elements (GRE). Western blotting and confocal microscopy of a green fluorescent protein-tagged-GR fusion protein demonstrated that arsenite pretreatment did not block the normal dexamethasone-induced nuclear translocation of GR. These data indicate that nontoxic doses of arsenite can interact directly with GR complexes and selectively inhibit GR-mediated transcription, which is associated with altered nuclear function rather than a decrease in hormone-induced GR activation or nuclear translocation.

Role of pre-operative assessment in the surgical management of leiomyoma extended to the right heart chambers: a compendium of information from isolated reports.

Recurrent intravenous leiomyoma extending to the right heart chambers is extremely rare. A large range of surgical techniques and approaches (i.e. two-step procedure, hypothermia and circulatory arrest) have been previously described. We report a recent case where the tumour was excised in a one-step procedure under normothermic cardiopulmonary bypass. This report associated to a comprehensive literature review allows us to discuss the role of pre-operative assessment and to propose refinement of surgical techniques according to the anatomy of the tumour.

Effects of qualitative and quantitative food restriction treatments on feeding motivational state and general activity level of growing broiler breeders.

Growing broiler breeder chickens are fed restricted rations to limit body weight at sexual maturity. This experiment tested a proposal (Brouns, F., Edwards, S.A., English, P.R., 1994. Effect of dietary fibre and feeding system on activity and oral behaviour of group housed gilts. Appl. Anim. Behav. Sci. 39, 215-223.) that feeding motivation is reduced by using qualitative rather than quantitative food restriction, and it examined relationships among suppression of growth rate, feeding motivational state and general activity level. From 2 to 15 weeks of age, female broiler breeders were reared in six groups of 20, each with a different feeding treatment. The six treatments were: high and low levels of diet dilution (600-700 g/kg and 300-350 g/kg oat feed, ad libitum), appetite suppression (50-60 g/kg and 25-30 g/kg calcium propionate, ad libitum) and quantitative restriction (recommended daily ration and twice that amount). Birds were conditioned to an operant (PR1 schedule) feeding procedure with their respective treatment diets from 3 to 7 weeks, and this was used to measure feeding motivation in 12-min tests at three times of day (1000, 1300 and 1600 h) at 8, 10, 12 and 14 weeks. Proportions of time spent sitting were measured as an index of general inactivity in systematic observations at 9, 11, 13 and 15 weeks. Although the diet dilution and appetite suppression (qualitative) treatments did not limit growth rates as intended, they and the quantitative treatments produced a range of mean body weights to compare with feeding motivation whenever birds were tested. With body weight as a covariate, there were significant effects on numbers of operant responses in 12 min (the measure of feeding motivation) of weight, age, time of day and treatmentxtime interaction, but not treatment. Feeding motivation was positively correlated with suppression of growth rate, regardless of how that suppression was achieved. However, the experimental procedure required all test birds to be without food from 0900 or 0915 h, and motivation was lowest in the earliest (1000 h) test with qualitative but not quantitative treatments. Hence, there was some evidence that feeding motivation may be partially suppressed with qualitative food restriction; distinction can be made between short-term and longer-term feeding motivation. General activity level (inversely reflected by time spent sitting) was closely correlated positively with both suppression of growth rate and feeding motivation. As a fundamental relationship between feeding motivation and reduction of growth rate was not altered by using qualitative rather than quantitative food restriction, these results support an earlier conclusion (Savory, C.J., Hocking, P.M., Mann, J.S., Maxwell, M.H., 1996. Is broiler breeder welfare improved by using qualitative rather than quantitative food restriction to limit growth rate? Anim. Welfare 5, 105-127.) that broiler breeder welfare is not improved with qualitative restriction methods.

Differential effects of arsenic(III) and chromium(VI) on nuclear transcription factor binding.

The toxic metals arsenic(III) and chromium(VI) are considered human carcinogens, although they may act through different mechanisms. We previously showed that when administered at single low, non-overtly toxic doses, chromium, arsenic, and several other chemical carcinogens preferentially alter expression of several model inducible genes in both whole-animal and cell-culture systems. In this study, we assessed whether chromium and arsenic target specific signaling pathways within cells to selectively modulate gene expression. We examined the effects of non-cytotoxic and cytotoxic doses of arsenic(III) and chromium(VI) on nuclear binding of the transcription factors AP-1, NF-kappaB, Sp1, and YB-1 in human MDA-MB-435 breast cancer and rat H4IIE hepatoma cells. These transcription factors were chosen because they may regulate many inducible genes, including those previously shown to be altered by metal treatments. We report that both arsenic and chromium significantly altered nuclear binding levels of these factors to their respective cis-acting elements. However, there were qualitative and quantitative differences in these effects that were dependent on the metal, time, dose, transcription factor, and cell line. These effects may play a significant role in metal-induced alterations in gene expression.

Effects of mitomycin C and carboplatin pretreatment on multidrug resistance-associated P-glycoprotein expression and on subsequent suppression of tumor growth by doxorubicin and paclitaxel in human metastatic breast cancer xenografted nude mice.

Overexpression of P-glycoprotein (Pgp), multidrug resistance-associated protein (MRP), and several other proteins has been associated with development of multidrug resistance by cancer cells, which represents a significant obstacle to successful treatment by chemotherapy. We had previously demonstrated that a single noncytotoxic dose of mitomycin C (MMC), carboplatin, or one of several other DNA cross-linking agents suppressed mRNA expression of the mdr1 gene coding for Pgp, leading to a subsequent suppression of Pgp protein levels and a concomitant decrease in drug efflux. Pretreatment with MMC led to a 5- to 10-fold decrease in the ED50 for cell killing by a subsequent agent such as the Pgp substrate, doxorubicin, but did not affect killing by the non-Pgp substrate, cisplatin. In this study, we report that MMC and carboplatin each significantly suppressed Pgp protein levels in human MDA-MB-435 cells xenografted as solid tumors into the lateral mammary fat pads of female nude mice, with a similar time course as had previously been observed in cell culture. Pretreatment of mice with MMC or carboplatin 48-72 h prior to receiving either doxorubicin or paclitaxel caused a significantly greater reduction in tumor growth rate compared to either agent alone or the combination given simultaneously. These data suggest that a combination chemotherapy regimen consisting of a DNA cross-linking agent given to modulate the MDR phenotype, followed by a second cytotoxic agent, may be an effective treatment for human patients with de novo or late stage acquired multidrug-resistant malignancies.

Molecular basis for effects of carcinogenic heavy metals on inducible gene expression.

Certain forms of the heavy metals arsenic and chromium are considered human carcinogens, although they are believed to act through very different mechanisms. Chromium(VI) is believed to act as a classic and mutagenic agent, and DNA/chromatin appears to be the principal target for its effects. In contrast, arsenic(III) is considered nongenotoxic, but is able to target specific cellular proteins, principally through sulfhydryl interactions. We had previously shown that various genotoxic chemical carcinogens, including chromium (VI), preferentially altered expression of several inducible genes but had little or no effect on constitutive gene expression. We were therefore interested in whether these carcinogenic heavy metals might target specific but distinct sites within cells, leading to alterations in gene expression that might contribute to the carcinogenic process. Arsenic(III) and chromium(VI) each significantly altered both basal and hormone-inducible expression of a model inducible gene, phosphoenolpyruvate carboxykinase (PEPCK), at nonovertly toxic doses in the chick embryo in vivo and rat hepatoma H411E cells in culture. We have recently developed two parallel cell culture approaches for examining the molecular basis for these effects. First, we are examining the effects of heavy metals on expression and activation of specific transcription factors known to be involved in regulation of susceptible inducible genes, and have recently observed significant but different effects of arsenic(III) and chromium(VI) on nuclear transcription factor binding. Second, we have developed cell lines with stably integrated PEPCK promoter-luciferase reporter gene constructs to examine effects of heavy metals on promoter function, and have also recently seen profound effects induced by both chromium(VI) and arsenic(III) in this system. These model systems should enable us to be able to identify the critical cis (DNA) and trans (protein) cellular targets of heavy metal exposure leading to alterations in expression of specific susceptible genes. It is anticipated that such information will provide valuable insight into the mechanistic basis for these effects as well as provide sensitive molecular biomarkers for evaluating human exposure.

Suppression of P-glycoprotein expression and multidrug resistance by DNA cross-linking agents.

Overexpression of the trans-membrane drug efflux pump P-glycoprotein is one of the major mechanisms by which cancer cells develop multidrug resistance. We demonstrated previously that noncytotoxic doses of various genotoxic chemicals, particularly DNA cross-linking agents, preferentially altered expression of inducible genes. These effects occurred principally at the transcriptional level and were closely correlated temporally with DNA damage. Because the mdr1 gene coding for P-glycoprotein has been reported to be highly inducible, we were interested in the effects of genotoxic cancer chemotherapy agents on its expression. We report that the DNA cross-linking agent mitomycin C significantly suppressed mRNA and protein expression of P-glycoprotein and decreased the rate of drug efflux. Mitomycin C pretreatment also significantly increased the sensitivity of cancer cells to subsequent killing by the P-glycoprotein substrate doxorubicin, decreasing the ED50 by 5- to 10-fold. Suppression of P-glycoprotein expression was also observed with subtoxic doses of the DNA cross-linking agents cisplatin, BMS181174, and chromium(VI). These effects occurred in both human and rodent cell lines; in cell lines derived from colon, breast, leukemia, neuroblastoma, and hepatoma tumors; and under both monolayer and "spheroid" culture conditions. These results suggest the basis for novel clinical cancer chemotherapy regimens aimed at drug-resistant tumors, in which a sub-chemotherapeutic dose of a DNA cross-linking agent is used to modulate the multidrug resistance phenotype prior to treatment with a second cytotoxic agent.

Patterns of changes in neutrophil adhesion molecules during normothermic cardiopulmonary bypass. A clinical study.

The adhesion of activated neutrophils to endothelial cells is a key feature of the inflammatory response to cardiopulmonary bypass (CPB) because it "unlocks" a cascade of cytotoxic events. This adhesion is made possibly by the sequential involvement of two sets of neutrophil cell surface receptors: L-selection and beta 2 integrins (CD 11 a/CD 18; CD 11 b/CD 18; CD 11 c/CD 18). We have assessed the changes in the expression of these adhesion molecules in ten patients who underwent various open-heart procedures with the use of "warm" (33.4 degrees-37 degrees C) CPB. Arterial blood samples were obtained before, during and after bypass and processed for immunofluorescent flow cytometric analysis. CD 11 a expression remained unchanged throughout the study period. Conversely, CD 11 b drastically increased early after the onset of bypass (at 15 min on bypass: 172 +/- 17 [mean fluorescence (arbitrary units), mean +/- SEM] versus 63 +/- 13 before bypass. P < 0.02) and was still markedly elevated 30 min after the end of bypass (160 +/- 38, P < 0.05 versus the pre-by-pass value). CD 11 c expression underwent a similar upregulation (at 15 min of bypass: 54 +/- 5 versus 34 +/- 5 at baseline, P < 0.01). L-selectin expression did not change significantly during the period of observation. Put together, these results suggest that CPB is associated with an increased adhesive potential of neutrophils, which enhances their binding to the vascular endothelium and thereby initiates tissue damage through the release of cytotoxic mediators from adherent cells. Manipulation of integrin expression could therefore represent an effective means of alleviating the component of bypass-induced inflammatory tissue damage which is more specifically neutrophil-mediated.

[Does temperature in extracorporeal circulation affect neutrophil-endothelium interactions?]. / La température de la circulation extracorporelle influence-t-elle les interactions neutrophiles-endothélium?

The increasing interest in "warm" aerobic cardioplegia requires a critical reevaluation of the systemic effects of the associated normothermic cardiopulmonary bypass (CPB). As activated neutrophils seem to be essential mediators of the inflammatory response to CPB via the cytotoxicity of the products that are released during their adhesion to endothelial cells, the authors undertook a study of the influence of temperature on the interaction between the neutrophils and the endothelium in 95 patients undergoing warm (31-33.5 degrees C, n = 49) and cold (26-27 degrees C, n = 46) CPB surgery. Blood sampling was performed before, during and after CPB. The following markers of neutrophil-endocardium interaction were analysed: complement activation (C3a), cytokine production (tumor necrosis factor alpha, interleukines 1, 6 and 8, and interleukin-1 receptor antagonist); endothelial expression of cytokine-dependent [intercellular adhesion molecule (ICAM)] and cytokine-independent (P-selectin) adhesion molecules (P-selectin); expression of cytokine molecules on the surface of polynuclear neutrophils (CD11a, CD11b, CD11c); and finally, endothelial adhesion and transendothelial migration of neutrophils (interleukin 8 and elastase). The results showed that, irrespective of temperature, CPB was associated with changes strongly suggestive of phenomena of transendothelial adhesion and migration. Moreover, normothermia increased the intensity of the inflammatory response as shown by increased cytokine production, earlier expression of neutrophil adhesion molecules and increased elastase production.

Therapeutic horseback riding:.

This paper reviews the literature on the benefits of therapeutic horseback riding and the outcomes of eleven data-based studies purpoting to validate the claims that horseback riding offers therapeutic benefits. These studies have focused on physical and psychosocial variables. The literature on the benefits of riding reported obvious beneficial effects, while the outcome studies were able to document only some of these claims. The studies generally reported some significant effects from the therapeutic intervention. An examination of the outcome studies revealed weak scientific rigor, small sample sizes, and a lack of homogeneous populations. Furthermore, use of standardized measures was limited as authors frequently relied on nonstandardized observational techniques to evaluate change. This review indicates a need for further research into both the physical and psychosocial areas with both children and adults. In addition, there is a need for research which would improve the methodological rigor, homogeneity of populations, sample size, and use of standardized measurement instruments.

A study of therapeutic effects of horseback riding for children with cerebral palsy.

This article describes major findings from a study of the therapeutic benefits of horseback riding for children with cerebral palsy. Nineteen children (aged 4-12 years) with mild or moderate degrees of cerebral palsy were recruited from a children's treatment centre. Prior to randomization, the children were stratified according to their degree of disability. Ten children were allocated to a riding (experimental) group, and participated in one-hour weekly riding classes for six months. The remaining nine children were put on a waiting list for riding. The results of the study were inconclusive as so often in the case with children with cerebral palsy. Qualitative results gleaned from the weekly progress recordings of the riding instructor, reports of the on-site physical therapist, and reports from parents showed clear progressions in physical and psychosocial functioning. Results of standardized quantitative assessments showed few statistically significant changes in the children. The study clearly indicates a need for further research and for finding or developing instruments that are able to capture and reveal meaningful changes in physical and psychosocial status.

Does normothermia during cardiopulmonary bypass increase neutrophil-endothelium interactions?

BACKGROUND: The use of warm blood cardioplegia is usually associated with that of warm cardiopulmonary bypass (CPB). Little is known, however, about the effect of temperature during bypass on neutrophil-endothelium interactions, which are currently considered a key component of the inflammatory response to CPB. METHODS AND RESULTS: Twenty-five patients operated on under CPB were studied. Core temperature during bypass was kept normothermic (33.5 degrees C to 37 degrees C) in 14 and lowered to 28 degrees C to 30 degrees C in the 11 remaining patients. The two groups were otherwise comparable. Arterial blood samples were collected before CPB and 30 minutes, 4 hours, and 24 hours thereafter. Samples were assayed for interleukin-1 receptor antagonist (IL-1ra), soluble intercellular adhesion molecule 1 (sICAM-1), and elastase, which are markers of cytokine production, cytokine-upregulated endothelial ligands for neutrophil adhesion molecules, and degranulation secondary to adhesion of neutrophils to endothelial cells, respectively. IL-1ra levels (mean +/- SEM) peaked 4 hours after bypass and were significantly higher in the warm group (87,926 +/- 24,067 versus 18,090 +/- 5798 mg/L, P < .02). Peak values of sICAM-1, which occurred 24 hours after bypass, were correspondingly higher in warm patients (414 +/- 74 versus 298 +/- 23 micrograms/L in cold patients). In keeping with these data, warm patients released significantly more elastase at both the 30-minute (703 +/- 101 versus 349 +/- 55 micrograms/L, P < .01) and 4-hour (627 +/- 116 versus 324 +/- 31 micrograms/L, P < .03) post-CPB study points. CONCLUSIONS: Temperature profoundly affects neutrophil-endothelium interactions, which leads one to question the use of systemic normothermia in patients at higher risk of suffering from postbypass inflammation-mediated organ damage.