Methodological considerations for aging research: Introduction to a symposium and methodological commentary

This article introduces a set of papers which illustrate the application or multivariate techniques to problems in aging research. Multivariate research strategies raise new issues in the choice of sample size that are discussed. The papers reviewed in this introduction are concerned with factorial invariance, the measurement of change, and various regression techniques useful in modeling developmental data.     

Ethical issues in rehabilitation: a qualitative analysis of dilemmas identified by occupational therapists

Little available research exists to address the range of ethical issues encountered by occupational therapists (OTs) in their daily clinical work. The few articles in the literature have tended to be case-based or anecdotal or have focused on professional issues rather than clinical issues. To characterize the array of clinical ethical issues in occupational therapy, we asked OTs in a free-standing academic rehabilitation hospital to describe in some detail up to three scenarios or situations from their clinical practice that raised morally troubling questions. A coding system was developed to preserve the richness of the detail but to allow for some categorization of the topics. A second section of the survey asked the therapists to rate whether various traditional ethics topics were of high, medium, or low interest to them. A third section asked that they identify the formats that would be most appealing to them for future educational interventions. Of the 56 therapists surveyed, 38 (or 68%) responded. The three self-generated topics mentioned most frequently by the therapists were (in decreasing order of frequency): reimbursement pressures, conflicts around goal setting, and patient/family refusal of team recommendations. The respondents were particularly interested in knowing more about patient-centered ethics topics, such as conflict resolution between teams and patients and the patient's role in decision making. Furthermore, they indicated a strong preference for interdisciplinary and interactive educational formats.     

Chromosomal aberrations in benign and malignant Bilharzia-associated bladder lesions analyzed by comparative genomic hybridization

Background

Bilharzia-associated bladder cancer (BAC) is a major health problem in countries where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study, we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions, and to determine whether their unique etiology yields a distinct cytogenetic profile as compared to chemically induced bladder tumors.

Methods

DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and 14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary bilharziasis were investigated for chromosomal imbalances using comparative genomic hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on paraffin sections of the same cases to confirm the CGH results.

Results

Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each, including the benign lesion.

Conclusion

Most of the detected imbalances have been repeatedly reported in non-bilharzial bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in bladder cancer in industrialized countries.

     

Vestibulo-ocular and optokinetic impairments in left unilateral neglect

Right brain damaged patients affected by left unilateral neglect (N+) typically fail to explore the contralesional space. For the first time, this study investigates the dynamic and spatial features of the horizontal vestibular-ocular response (VOR), the optokinetic response (OKR) and the VOR-OKR interaction in six N+ and in five right brain damaged patients without neglect (N-). No lateral asymmetry of the gain (i.e. eye velocity to head velocity ratio) of VOR slow phases was found in either group. In the VOR, N+ had higher frequency of slow-rightward/fast-leftward phases and higher contralesional shift of the beating field (i.e. orbital position of fast phases). In the VOR-OKR, there was an increase of gain in both lateral directions and in both groups even though in N-, there was a lower phase shift between eye and head velocity. In contrast to the VOR, in the VOR-OKR, N+ had higher frequency of slow-leftward/fast-rightward phases. The VOR-OKR interaction also introduced an ipsilesional shift of the beating field in both N+ and N-. In the OKR, N+ showed a drop in the velocity, amplitude and frequency of slow-rightward/fast-leftward phases. These findings potentially suggest that each hemisphere modulates VOR with contralaterally directed slow phases and OKR with ipsilaterally directed slow phases. This organisation could facilitate maintenance or fast recovery of combined VOR + OKR after unilateral brain damage. The same findings suggest that by inducing slow-leftward phases, vestibular and optokinetic stimulation improve left side neglect through the activation of different hemispheric pathways. No ipsilesional deviation of the subjective "straight ahead" was found in N+. These results show that chronic unilateral neglect can be dissociated both from deficits of ipsilesionally directed VOR and from ipsilesional deviation of the subjective midsagittal plane of the body.     

Biomechanical evaluation of the efficacy of external stabilizers in the conservative treatment of acquired flatfoot deformity

This study quantified and compared the efficacy of in-shoe orthoses and ankle braces in stabilizing the hindfoot and medial longitudinal arch in a cadaveric model of acquired flexible flatfoot deformity. This was addressed by combining measurement of hindfoot and arch kinematics with plantar pressure distribution, produced in response to axial loads simulating quiet standing. Experiments were conducted on six fresh-frozen cadaveric lower limbs. Three conditions were tested: intact-unbraced; flatfoot-unbraced; and flatfoot-braced. Flatfoot deformity was created by sectioning the main support structures of the medial longitudinal arch. Six different braces were tested including two in-shoe orthoses, three ankle braces and one molded ankle-foot orthosis. Our model of flexible flatfoot deformity caused the calcaneus to evert, the talus to plantarflex and the height of the talus and medial cuneiform to decrease. Flexible flatfoot deformity caused a pattern of medial shift in plantar pressure distribution, but minimal change in the location of the center of pressure. Furthermore, in-shoe orthoses stabilized both the hindfoot and the medial longitudinal arch, while ankle braces did not. Semi-rigid foot and ankle orthoses acted to stabilize the medial longitudinal arch. Based on these results, it was concluded that treatment of flatfoot deformity should at least include use of in-shoe orthoses to partially restore the arch and stabilize the hindfoot.