Nicotine alters striatal glutamate function and decreases the apomorphine-induced contralateral rotations in 6-OHDA-lesioned rats

The overall goal of this study was to determine the effects of subchronic nicotine (0.4 mg/kg) treatment for 7 or 14 days on striatal glutamate function in both na?ve and in 6-hydroxydopamine (6-OHDA)-treated rats in which the nigrostriatal dopamine pathway was lesioned. In lesioned animals, the effect of nicotine on apomorphine-induced contralateral rotations was also assessed. In na?ve rats, once daily nicotine administration for 7 or 14 days resulted in a decrease and then an increase, respectively, in the basal extracellular level of striatal glutamate compared to the saline-treated group. Ultrastructurally, 14-day treatment with nicotine resulted in an increase in the density of striatal glutamate immunolabeling within nerve terminals making an asymmetrical synaptic contact compared to the saline-treated group. In 6-OHDA-lesioned animals, coadministration of nicotine with apomorphine or nicotine alone for 7 days resulted in an increase in the density of nerve terminal glutamate immunolabeling, compared to the apomorphine- or saline-treated groups. However, coadministration of nicotine with apomorphine for 14 days resulted in a decrease in the density of nerve terminal glutamate immunolabeling compared to the nicotine-treated group. Following subchronic treatment of 6-OHDA-lesioned rats with apomorphine for 7 or 14 days, there was an increase in the number of apomorphine-induced contralateral rotations compared to the saline treated group. There was a decrease in the number of apomorphine-induced contralateral rotations in the group coadministered nicotine with apomorphine for 7 or 14 days compared to the apomorphine treated group. The data suggests that in this 6-OHDA lesion model of Parkinson's disease, treatment with nicotine may be useful in counteracting the increased behavioral effect (i.e., contralateral rotations) observed after treatment with a dopamine agonist, such as apomorphine.     

Both dorsal and ventral spinal cord pathways contribute to overground locomotion in the adult rat

Identification of long tracts responsible for spontaneous locomotion is critical for spinal cord injury (SCI) repair strategies. We recently demonstrated that extensive demyelination of adult rat thoracic ventral columns, ventromedial, and ventrolateral white matter produces persistent, significant open-field hindlimb locomotor deficits. Locomotor movements resulting from stimulation of the pontomedullary locomotor region are inhibited by dorsolateral funiculus (DLF) lesions suggesting that important pathways for locomotion may also exist in the dorsal white matter. However, dorsal hemisections that interrupt dorsal columns/dorsal corticospinal tract (DC/CST) and DLF pathways do not produce persistent, severe locomotor deficits in the adult rat. We studied the contributions of myelinated tracts in the DLF and DC/CST to overground locomotion following complete conduction blockade of axons in the ventrolateral funiculus (VLF), a region important for locomotor movements and for transcranial magnetic motor-evoked potentials (tcMMEP). Animals received ethidium bromide plus photon irradiation to produce discrete demyelinating lesions sufficient to stop axonal conduction in the VLF, combined VLF + DLF, or combined VLF + DC/CST. Open-field BBB scores and tcMMEPs were studied at 1, 2, 3, and 4 weeks postlesion. VLF lesions resulted in mean BBB scores of 17 at 4 weeks. VLF + DC/CST and VLF + DLF lesions resulted in mean BBB scores of 15.9 and 11.1, respectively. TcMMEPs were absent in all lesion types confirming VLF conduction blockade throughout the study. Our data indicate that significant contributions to locomotion from myelinated pathways within the rat DLF can be revealed when combined with simultaneous compromise of the VLF.     

Temporal progression of angiogenesis and basal lamina deposition after contusive spinal cord injury in the adult rat

After spinal cord injury (SCI), the absence of an adequate blood supply to injured tissues has been hypothesized to contribute to the lack of regeneration. In this study, blood vessel changes were examined in 28 adult female Fischer 344 rats at 1, 3, 7, 14, 28, and 60 days after a 12.5 g x cm NYU impactor injury at the T9 vertebral level. Laminin, collagen IV, endothelial barrier antigen (SMI71), and rat endothelial cell antigen (RECA-1) immunoreactivities were used to quantify blood vessel per area densities and diameters in ventral gray matter (VGM), ventral white matter (VWM), and dorsal columns (DC) at levels ranging 15 mm rostral and caudal to the epicenter. This study demonstrates an angiogenic response, defined as SMI71/RECA-1-immunopositive endothelial cells that colocalize with a robust deposition of basal lamina and basal lamina streamers, 7 days after injury within epicenter VGM. This angiogenesis diminishes concurrent with cystic cavity formation. GAP43- and neurofilament- (68 kDa and 210 kDa) immunopositive fiber outgrowth was associated with these new blood vessels by day 14. Between 28 and 60 days after injury, increases in SMI71-immunopositive blood vessel densities were observed in the remaining VWM and DC with a corresponding increase in vessel diameters up to 15 mm rostral and caudal to the epicenter. This second angiogenesis within VWM and DC, unlike the acute response observed in VGM, did not correspond to any previously described changes in locomotor behaviors in this model. We propose that therapies targeting angiogenic processes be directed at the interval between 3 and 7 days after SCI.     

Pedigree Selection and Tests of Linkage in a Hutterite Asthma Pedigree

We explored methods for kinship and linkage analysis in a Hutterite pedigree comprising 1,544 individuals, 72 of whom were diagnosed with asthma. Subpedigrees were selected by (a) identifying nuclear families containing asthmatics, (b) identifying couples with many asthmatic descendants in an ad hoc manner, and (c) finding the most recent common ancestors of all asthmatics. Markov chain Monte Carlo (MCMC) methods were used to estimate allele sharing in the larger subpedigrees and transmission/disequilibrium tests were performed on nuclear families. On chromosome 5q near the cytokine cluster, modest evidence for linkage to asthma was obtained. Using MCMC, we were able to evaluate the evidence for linkage in complex subpedigrees of several hundred individuals, and hence, incorporate some of the co‐ancestry of this founder population. © 2001 Wiley‐Liss, Inc.     

Effects of a family intervention on the quality of life of women with recurrent breast cancer and their family caregivers

BACKGROUND: The purpose of this study was to determine if patients with advanced breast cancer and their family caregivers, who participated in a family based intervention, report better quality of life and other psychosocial outcomes than dyads who received standard care alone. METHODS: Using a randomized clinical trial, 134 patients and their family caregivers were assigned to usual care (control) or to usual care plus the family intervention (experimental condition). Dyads were assessed at baseline, three- and six-months later. The intervention consisted of five sessions and addressed family involvement, optimistic attitude, coping effectiveness, uncertainty reduction, and symptom management. RESULTS: Patients in the family intervention reported significantly less hopelessness and less negative appraisal of illness than controls; their family caregivers reported significantly less negative appraisal of caregiving. Intervention effects were evident at three-months, but were not sustained at six-months. No difference was found in the quality of life of dyads in experimental or control conditions. CONCLUSIONS: Although the family intervention had positive effects initially, these effects were not sustained over time. Future studies need to consider program dose and duration of effect, outcome measures that are more sensitive to change, and realistic end-points for patients with advanced cancer.     

Physiology of thermoregulatory dysfunction and current approaches to the treatment of vasomotor symptoms

Vasomotor symptoms (VMS), including hot flushes and night sweats, are the most common symptoms associated with menopause. Although the physiology of hot flushes is not fully defined, understanding the complex thermoregulatory circuitry that underlies VMS is important for the development of new therapies. This circuitry is composed of three distinct, yet interconnected, components: core body temperature, neurochemical messaging and peripheral vasculature. Evidence suggests that multiple physiological systems, including the neuroendocrine system, are important in the maintenance of thermoregulatory control. Causative roles of declining ovarian steroid levels in initiating thermoregulatory dysfunction are well documented. This paper reviews the physiology involved in the underlying thermoregulatory dysfunction that presumably causes VMS and discusses how this physiology relates to current and future VMS treatment options.     

Thrombophilia and the risk for hemodialysis vascular access thrombosis

Vascular access thrombosis is the most common and costly complication in hemodialysis patients. The role of thrombophilia in access thrombosis is not established. A case-control study was conducted of 419 hemodialysis patients to determine whether thrombophilia was associated with arteriovenous fistula or graft thrombosis. Participants were enrolled from three in-center and five satellite dialysis units associated with a Canadian academic health science center that provides dialysis services in a catchment area of one million. Patients were tested for factor V Leiden, prothrombin gene mutation, factor XIII genotype, methylenetetrahydrofolate reductase genotype, lupus anticoagulant, anticardiolipin antibody, factor VIII, homocysteine, and lipoprotein (a) concentrations. Overall, 59 (55%) patients with access thrombosis had at least one thrombophilia compared with 122 (39%) patients without access thrombosis (unadjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.23 to 2.98). After controlling for important risk factors, the association between any thrombophilia and access thrombosis remained (adjusted OR, 2.42; 95% CI, 1.47 to 3.99). For each additional thrombophilic disorder, the odds of access thrombosis increased significantly (adjusted OR, 1.87; 95% CI, 1.34 to 2.61). This study suggests that thrombophilia is associated with access thrombosis in dialysis patients. Large, multicenter, prospective cohort studies are needed to confirm the observations from this case-control study.     

Canadian physical therapists' interest in web-based and computer-assisted continuing education

BACKGROUND AND PURPOSE: Distance education via computer-assisted learning (CAL), including Web-based and CD-ROM learning, confers a number of advantages compared with traditional learning methods. The purposes of this study were (1) to determine the interest of Canadian physical therapists in participating in continuing education using CAL methods and (2) to determine whether interest in CAL was related to type of employment, area of practice, education, computer skill and access, and other demographic variables. SUBJECTS AND METHODS: A random sample of Canadian physical therapists and all members of cardiopulmonary interest groups were surveyed. RESULTS: Of 1,426 survey questionnaires mailed, 69 were returned (58 were unopened and 11 were duplicates). From the remaining 1,357 potential survey responses, 757 responses were received, for an overall response rate of 56%. Seventy-eight percent of the respondents indicated their interest in participating in CAL. Factors associated with interest in CAL included 2 or more hours of Internet access per week, Internet access at both home and work, computer skill, education level, practice area, and belonging to a cardiopulmonary interest group. DISCUSSION AND CONCLUSION: The findings indicate a large positive interest in CAL. Increasing CAL continuing education opportunities could increase options for physical therapists to meet professional expectations for continuing competency.