Determinants of gait as applied to children with cerebral palsy.

In the present study, we quantified the isolated contributions of eight determinants of gait on the vertical center of mass (CoM) displacement of both typically developing children and children with cerebral palsy (CP). The role of these determinants, on vertical excursion, has never been examined for children or children with CP. We hypothesized that the relative contributions of the determinants to vertical CoM excursion of children with CP would be the same as the age-matched controls. We found that based on the similarities in the determinants effect on gait between the controls and adults reflect that children of this age walk with a mature gait. When applied to subjects with CP the determinant analysis found similar, but slightly exaggerated effects of those of the controls. All determinants that negatively affect CoM excursion were significantly worse in the children with CP, while those determinants that decreased excursion were varied. Heel rise, single support knee flexion, and pelvic obliquity had similar effects for on both groups. Pelvic rotation resulted in more excursion reduction in the controls, while leg inclination was more beneficial in reducing the CP groups excursion. The main cause for increased vertical excursion of the CoM in the children with CP was the increased knee flexion of both legs during double support. This excessive lowering of the CoM means that extra work is done to raise the CoM over the single support leg. The situation is aggravated by the fact that the CoM was lifted higher than typical because of the heel lifting during single support. Although these determinants allow quantification of the effects of gait kinematics and provide some useful information for gait they are limited in their ability to quantify the dynamics and kinetics of gait that are important for individuals with walking disabilities.

Paraspinal muscle reflex dynamics.

Neuromuscular control of spinal stability may be represented as a control system wherein the paraspinal muscle reflex acts as feedback response to kinetic and kinematic disturbances of the trunk. The influence of preparatory muscle recruitment for the control of spinal stability has been previously examined, but there are few reported studies that characterize paraspinal reflex gain as feedback response. In the current study, the input-output dynamics of paraspinal reflexes were quantified by means of the impulse response function (IRF), with trunk perturbation force representing the input signal and EMG the output signal. Surface EMGs were collected from the trunk muscles in response to a brief anteriorly directed impact force applied to the trunk of healthy participants. Reflex behavior was measured in response to three levels of force impulse, 6.1, 9.2 and 12.0 Ns, and two different levels of external trunk flexion preload, 0 and 110 N anterior force. Reflex EMG was quantifiable in response to 91% of the perturbations. Mean reflex onset latency was 30.7+/-21.3 ms and reflex amplitude increased with perturbation amplitude. Impulse response function gain, G(IRF), was defined as the peak amplitude of the measured IRF and provided a consistent measure of response behavior. EMG reflex amplitude and G(IRF) increased with force impulse. Mean G(IRF) was 2.27+/-1.31% MVC/Ns and demonstrated declining trend with flexion preload. Results agree with a simple systems model of the neuromechanical feedback behavior. The relative contribution of the reflex dynamics to spinal stability must be investigated in future research.

Hope, Arkansas to Hope, Albania: naivete and idealism to reality and tragedy.

The wars in Croatia, Bosnia and Kosovo were perpretrated by a radical nationalist Serbian cultural political consciousness that the American cultural political consciousness and leadership had difficulty responding to and understanding. There is a great cultural divide between a 'pathology' in Serbian culture, Milosevic's radical nationalism, and a humane 'naivete' in American cultural consciousness. I discuss why, finally, American political leadership, Bill Clinton from Hope, Arkansas, responded to the tragedy of these wars. However, we are still left with the question of good vs evil: What is the course of human history; psychotic political leadership causing repetitive human tragedy or can there be a higher humane and moral order to human cultural events?

The international flow of cultural capital and an American anthropologist's experiences doing ethnography in Croatia: the insider/outsider question.

This essay is a discussion of the author's changing perspectives of his anthropological research in Croatia which comes about through the postmodern critique of theorectical paradigms as well as the fact that financial and cultural globalization has changed the subject of our research. Added to the globalization process and the international flow of cultural capital in Croatia are the recent events of the collapse of a modernism experiment in Marxism and the emergence of ethnic nationalism. The complexity of these current postmodern trends in theorectical anthropology, combined with complex current historical processes on top of a very complex history in Croatia, raise real questions about whether or not the outsider anthropologist can textualize the cultural situation here. But, a question still remains as to whether the insider anthropologist/ethnologist can textualize a cultural situation that is difficult to draw parameters around because of the international flow of cultural capital, e.g., are the younger generation really focused on localized ethnic nationalism or is this now a situation that is so internationalized that our former assumptions about local place make no longer make sense?

Surgical resection for management of renal cancer with hepatic involvement.

PURPOSE: More than 900 patients who underwent hepatic resections were reviewed to identify those whose liver resections were due to involvement by renal cell carcinoma. MATERIALS AND METHODS: Three patients with direct hepatic extension of the renal cell cancer underwent radical nephrectomy with en bloc partial hepatectomy, while 1 with a metachronous recurrence 3 years after nephrectomy underwent right triple lobe hepatectomy. There were no postoperative complications. RESULTS: Of the en bloc resections 2 showed sarcomatoid features on histopathological examination. These patients experienced rapid disease progression and died. The remaining 2 patients with typical clear cell carcinoma have no evidence of disease. CONCLUSIONS: Experience with these 4 patients has demonstrated that hepatic resection is technically feasible and associated with acceptable morbidity rates. Surgical management should be considered in patients with the uncommon presentation of renal cell carcinoma and localized hepatic involvement.

Neural control of urethral outlet activity in vivo: role of nitric oxide.

The present study investigated the role of nitric oxide (NO) in the reflex changes in urethral outlet activity during micturition. Isovolumetric bladder contractions, urethral pressure and external urethral sphincter electromyogram (EUS EMG) activity were recorded independently in urethane-anesthetized rats. During reflex bladder contractions, the urethra exhibited reflex responses characterized by an initial decrease in urethral pressure in conjunction with a rise in bladder pressure. This was followed by a period of high frequency oscillations (HFOs) associated with maximal urethral relaxation and burst type EUS EMG activity. Administration of N-nitro-L-arginine (L-NOARG) 10 mg./kg. intravenously, a nitric oxide synthase inhibitor, reversibly decreased the magnitude (62%, p < 0.05) and duration (40%, p < 0.05) of reflex urethral relaxation (N = 7). In 4 additional experiments, L-NOARG (10 to 15 mg./kg. intravenously) completely eliminated reflex urethral relaxation during micturition, and this effect was reversed in all animals by the administration of L-arginine (100 to 150 mg./kg. intravenously). Administration of N-nitro-D-arginine (D-NOARG) (10 to 30 mg./kg. intravenously) had no effect on reflex urethral relaxation. Neuromuscular blockade (vecuronium bromide 5 mg./kg. intravenously) reversibly decreased resting urethral pressure and eliminated the HFOs. The urethral smooth muscle relaxation that remained after neuromuscular blockade was eliminated following administration of L-NOARG (10 mg./kg. intravenously) in 2 of 3 animals. These results suggest that reflex urethral responses during micturition involve changes in both smooth and striated muscle activity, and that the predominant neurotransmitter mechanisms that mediate reflex urethral smooth muscle relaxation involve NO.