Impact of heterozygous ALK1 mutations on the transcriptomic response to BMP9 and BMP10 in endothelial cells from hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension donors

Heterozygous activin receptor-like kinase 1 (ALK1) mutations are associated with two vascular diseases: hereditary hemorrhagic telangiectasia (HHT) and more rarely pulmonary arterial hypertension (PAH). Here, we aimed to understand the impact of ALK1 mutations on BMP9 and BMP10 transcriptomic responses in endothelial cells. Endothelial colony-forming cells (ECFCs) and microvascular endothelial cells (HMVECs) carrying loss of function ALK1 mutations were isolated from newborn HHT and adult PAH donors, respectively. RNA-sequencing was performed on each type of cells compared to controls following an 18 h stimulation with BMP9 or BMP10. In control ECFCs, BMP9 and BMP10 stimulations induced similar transcriptomic responses with around 800 differentially expressed genes (DEGs). ALK1-mutated ECFCs unexpectedly revealed highly similar transcriptomic profiles to controls, both at the baseline and upon stimulation, and normal activation of Smad1/5 that could not be explained by a compensation in cell-surface ALK1 level. Conversely, PAH HMVECs revealed strong transcriptional dysregulations compared to controls with > 1200 DEGs at the baseline. Consequently, because our study involved two variables, ALK1 genotype and BMP stimulation, we performed two-factor differential expression analysis and identified 44 BMP9-dysregulated genes in mutated HMVECs, but none in ECFCs. Yet, the impaired regulation of at least one hit, namely lunatic fringe (LFNG), was validated by RT-qPCR in three different ALK1-mutated endothelial models. In conclusion, ALK1 heterozygosity only modified the BMP9/BMP10 regulation of few genes, including LFNG involved in NOTCH signaling. Future studies will uncover whether dysregulations in such hits are enough to promote HHT/PAH pathogenesis, making them potential therapeutic targets, or if second hits are necessary.

SB-258585 reduces food motivation while blocking 5-HT6 receptors in the non-human primate striatum

The interest in new 5-HT₆ agents stems from their ability to modulate cognition processing, food motivation and anxiety-like behaviors. While these findings come primarily from rodent studies, no studies on primates have been published. Furthermore, our understanding of where and how they act in the brain remains limited. Although the striatum is involved in all of these processes and expresses the highest levels of 5-HT₆ receptors, few studies have focused on it. We thus hypothesized that 5-HT6 receptor blockade would influence food motivation and modulate behavioral expression in non-human primates through striatal 5-HT6 receptors. This study thus aimed to determine the effects of acute administration of the SB-258585 selective 5-HT6 receptor antagonist on the feeding motivation and behaviors of six male macaques. Additionally, we investigated potential 5-HT6 targets using PET imaging to measure 5-HT6 receptor occupancy throughout the brain and striatal subregions. We used a food-choice task paired with spontaneous behavioral observations, checking 5-HT6 receptor occupancy with the specific PET imaging [18F]2FNQ1P radioligand. We demonstrated, for the first time in non-human primates, that modulation of 5-HT6 transmission, most likely through the striatum (the putamen and caudate nucleus), significantly reduces food motivation while exhibiting variable, weaker effects on behavior. While these results are consistent with the literature showing a decrease in food intake in rodents and proposing that 5-HT6 receptor antagonists can be used in obesity treatment, they question the antagonists' anxiolytic potential.

Influence of Roulez avec confiance, a peer-led community-based wheelchair skills training program, on manual wheelchair users

PURPOSE

Few studies have demonstrated that peer-led manual wheelchair (MWC) skills training can increase MWC skills, MWC use self-efficacy and satisfaction with participation of MWC users. Limited information is available on MWC skills training in the community. The primary objective was to measure the influence of Roulez avec confiance (RAC, which translated to "Wheeling with confidence"), a peer-led community-based wheelchair skills training program, on satisfaction with participation. The secondary objectives were to explore the: (1) influence of RAC on MWC use self-efficacy, MWC skills, and quality of life; (2) experiences of the participants who completed RAC and (3) three-month retention of outcomes.

METHODS

A parallel mixed design was used with validated questionnaires on satisfaction with participation (WhOM), MWC use self-efficacy (WheelCon-M), MWC skills (WST-Q), quality of life (SWLS) and a semi-structured interview on participants' experiences. Non-parametric longitudinal analyses of the questionnaires and thematic content analysis of the interviews were completed.

RESULTS

Nineteen community-dwelling MWC users participated. There was a statistically significant increase (p < 0.0001) in all outcomes except quality of life (p = 0.16). Improvements were retained after three months. Participants mentioned their background influenced their experiences in RAC. Positive elements about RAC and areas for improvement were discussed. Participants reported overall positive social experiences and stated that the physical environment influenced RAC. Finally, participants spoke about what they learned and emotions they felt during RAC.

CONCLUSIONS

Peer-led community-based MWC training influenced satisfaction with participation, MWC skills, and MWC use self-efficacy. This study was a first step in demonstrating the efficiency of RAC.IMPLICATIONS FOR REHABILITATIONLimited information is available on manual wheelchair skills training in the community.Peer-led community-based manual wheelchair training influenced satisfaction with participation, manual wheelchair skills and use self-efficacy.This study was a first step in demonstrating the efficiency of Roulez Avec Confiance.

Potential assistive technology preferences of informal caregivers of people with disability

Background

Preferences of informal caregivers of people with neurocognitive disorders for technological solutions are important in user- centered design approaches. It is crucial to take into consideration the needs and preferences of users when developing new technology to facilitate their uptake.

Objectives

The objective of this study was to determine caregiver preferences for potential technological solutions to help address their needs and compare technology preferences of caregivers who provide care to those with and without neurocognitive disorders (NCD).

Methods

This was a quantitative descriptive study. We surveyed informal caregivers of older adults with disability in Canada. Participants were asked to answer questions about their preferences for 10 potential technological solutions that could be developed to make caregiving easier.

Results

Data from 125 respondents (72 caregivers of people with NCD and 53 caregivers of people with non-NCD-related disabilities) were analyzed. Generally, caregivers preferred web-based solutions as these were among the first five choices for both groups combined. However, there were some differences in the order of preference of potential solutions in both groups.

Conclusion

Informal caregivers of people with NCD preferred web-based solutions to help address their needs.

Prediction of quality of life in schizophrenia using machine learning models on data from clinical antipsychotic trials of intervention effectiveness (CATIE) schizophrenia trial

Introduction

Schizophrenia is a chronic and severe mental disorder. While research focus remains mainly on negative outcomes, it is questionable whether we are placing enough emphasis on improving their sense of well-being and functioning. This could be accessed through the study of the quality of life (QoL). To date, QoL prediction models mainly focused on neurocognition and psychotic symptoms, but their predictive power remained limited.

Objectives

The aim is to accurately predict the QoL within schizophrenia using unsupervised learning methods.

Methods

We computed variables from 952 patients from the CATIE study, a randomized, double-blind clinical trial for schizophrenia treatment. QoL was measured using the Heinrichs-Carpenter Quality of Life Scale and potential predictors included almost all available variables: symptoms, neurocognition, medication adherence, insight, adverse effects, etc. By optimizing parameters to reach optimal models, three linear regressions were calculated: (1) baseline predictors of 12-month QoL, (2) 6-month predictors of 12-month QoL, and (3) baseline predictors of 6-month QoL. Adjustments were made to ensure that included variables were not collinear nor redundant with QoL.

Results

Calculated models had adjusted R-squared of 0.918, 0.922 and 0.913, respectively. Best predictors were medication side effects, sociodemographic and neurocognitive variables. Low psychotic and depressive symptoms were also included, as well as lab values suggesting the absence of problems with chloremia and calcemia.

Conclusions

Calculated predictive models explain almost all subsequent QoL. It appears that physical health variables, generally omitted from mental health-related studies, have an important impact on patients’ QoL. Therefore, interventions should also consider these aspects.

Disclosure

No significant relationships.

Usability of the Participation and Quality of Life (PAR-QoL) Outcomes Toolkit Website for Spinal Cord Injury

Background: Quality of life (QoL) is an important parameter to monitor during rehabilitation; however, accurate assessment is challenging. Among individuals with spinal cord injury (SCI), assessing QoL is further challenged due to complex sequelae, such as secondary health conditions and factors related to community integration. A Participation and Quality of Life (PAR-QoL) toolkit was created to aid clinicians and researchers in the selection of QoL outcomes tools specific to SCI. Objectives: The aim of this study was to evaluate the use and usability of the PAR-QoL toolkit. Methods: A cross-sectional study was conducted using an online survey from December 2013 to November 2016. Google Analytics were collected from April 2012 to April 2018. Survey sections addressed "use" (behavioral practices and actual use) and "usability" (perceived ease of use and perceived usefulness). Any person who visited the PAR-QoL website was invited to complete the survey. Summary statistics and percent concordances were calculated to describe results from the survey and Google Analytics. Results: The PAR-QoL website had 188,577 users. The five most visited webpages were outcome tools, with bounce rates ranging from 77% to 90%. Of the 46 survey respondents, 67% were not current users of the PAR-QoL website, and 87% intended to use the resources in the future. Conclusion: Uptake of the PAR-QoL website is currently limited. Usability of the PAR-QoL website may be improved by modifying navigation, removing the "less useful" components, ensuring regular updates of content and resources, and promoting the website.

Technical quality of online resources for mobility device training

Purpose: Training is recommended to improve safe and effective use of mobility aids. The internet offers a large amount of information and it can be difficult to identify resources with good quality. This project aimed to create a catalogue of online educational resources for mobility device training. The objective of this study was to identify and assess the quality of existing online educational resources for mobility device training for individuals with physical disabilities and caregivers.Methods: A Google search was conducted in October 2016 and replicated in January 2018. Resources were included if they were educational, were available in English or French, provided instruction or training in mobility aid use, were free of charge, and were targeted towards mobility device users or their caregivers. Resources were assessed using a modified version of the Journal of the American Medical Association (JAMA) benchmarks for the evaluation of technical quality.Results: Two hundred and seventy-one resources were included in the final analysis. Two resources were added by the research team for a total of 273 resources. The average JAMA quality score per mobility device varied between 3 (for crutches) and 5 (for knee scooters) out of 6, and weighted average was 3.6. The two resources added by the research team obtained a JAMA quality score of 6. 58 resources were retained for the catalogue.Conclusions: The results suggest that the technical quality of online educational resources for mobility device training could be improved. A need for higher quality resources for device users and caregivers was identified.Implications for rehabilitationThe overall technical quality of online educational resources for mobility device training for users and caregivers is low.A Mobility Device Training Catalogue is freely available and summarizes the highest quality online resources found on mobility device training.The Mobility Device Training Catalogue is intended for use by users and caregivers, but it may also provide clinicians with a tool that may be shared with their clients.

Influence of peer-based rehabilitation interventions for improving mobility and participation among adults with mobility disabilities: a systematic review

Purpose: The prevalence of mobility disability reaches up to 20.5% among older adults. Mobility is a key factor of participation, thus rehabilitation interventions often aim to improve mobility and participation. Peer-based approaches to intervention delivery have become increasingly common. This study aims to identify peer-based rehabilitation interventions and summarize their influence on mobility and participation among individuals with mobility disabilities.Method: A systematic review was conducted using CINALH, EMBASE, MEDLINE, and PsycINFO. Articles that evaluated peer-based rehabilitation interventions for individuals with a mobility disability and assessed mobility or participation, as defined in the International Classification of Functioning, Disability and Health framework, were included. Study quality was assessed using the Physical Therapy Evidence Database and the Quality Assessment Tool for Before-After Studies With No Control Group.Results: Thirteen peer-based studies were identified. Six peer-led studies evaluated participation and two evaluated mobility. Seven professional-led studies evaluated participation and six evaluated mobility. Randomized controlled trials had fair to high quality. The quality of pre-post studies ranged from poor to good.Conclusion: Peer-based interventions should not be overlooked as a potential intervention strategy, but further research is needed to establish their influence on mobility and participation.Implications for rehabilitationPeers offer a unique model of intervention that could support clinicians in their effort to improve mobility and participation outcomes for individuals with disabilities.There are currently two main models of peer-based interventions in rehabilitation: professional-led (peers assist professionals to facilitate the intervention) and peer-led interventions (peers facilitate the intervention).Both professional-led and peer-led models of intervention could be helpful in facilitating participation and in increasing mobility.

Impacts of robotic arm use on individuals with upper extremity disabilities: A scoping review

BACKGROUND.

Robotic arms may help users perform various activities. Even though robotic arms are commercially available, their impacts are still poorly understood.

PURPOSE.

This scoping review aimed to identify the potential impacts of using robotic arms for individuals with upper-extremity disabilities and appraise the scientific quality of the selected studies.

METHOD.

A search for studies published between 1970 and 2016 was conducted in PubMed, Embase, Compendex, and Scopus. The Canadian Model of Occupational Performance and Engagement was used to classify activities in which impacts were evaluated. The quality of each study was rated using McMaster University's critical review form for quantitative studies.

FINDINGS.

Thirty-six studies were reviewed, which evaluated self-care (21), productivity (33), and leisure (8). The short-term impacts were more commonly documented than long-term impacts. The impacts identified were mostly positive. The studies' mean quality score was 8.8/15.

IMPLICATIONS.

Additional studies with more rigorous conditions are needed to produce higher-quality scientific evidence of the long-term impacts of robotic arm use.

Psychometric properties of the Community Integration Questionnaire: a systematic review of five populations

OBJECTIVES

This systematic review documents the content and the quality of the psychometric evidence concerning the utilization of the Community Integration Questionnaire for individuals living with a disability other than a traumatic brain injury.

DATA SOURCES

Medline, Embase, CINAHL, OTseeker and PsycINFO (searched from inception to June 2019).

REVIEW METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used for conducting and reporting this review. Studies that investigated at least one psychometric property of the Community Integration Questionnaire for individuals living with a disability other than traumatic brain injury were included. Data extraction and critical methodological appraisal of the articles (MacDermid checklist, COnsensus-based Standards for the selection of health Measurement INstruments checklist) were independently performed and validated by the first two authors.

RESULTS

Ten studies representing 3000 individuals met the inclusion criteria. Five populations were documented. There are positive and trustable data regarding internal consistency for adults living with multiple sclerosis, spinal cord injury or burns and in mixed samples (α = 0.71-0.84). Construct validity is fairly documented for adults living with multiple sclerosis or aphasia and in mixed samples. Test-retest reliably is acceptable for adults living with multiple sclerosis (intraclass correlation coefficient = 0.91-0.97) as well as responsiveness (area under the receiver operating characteristic curve = 0.81). Other psychometric properties could not be demonstrated sufficiently solid.

CONCLUSION

Many psychometric properties of the Community Integration Questionnaire are still poorly evaluated for adults living with a disability other than a traumatic brain injury. However, promising data have been documented in each population included in this review.

Long-term use of the JACO robotic arm: a case series

PURPOSE

Past research with JACO has principally focused on the short-term impacts on new users. Therefore, this study aims to document the long-term impacts of this assistive device on users and their family caregivers following prolonged use.

METHODS

Users' characteristics, caregivers' characteristics and expenses related to JACO were documented with questionnaires designed for this study. Upper extremity performance was measured with an adaptation of an upper extremity performance test, the TEMPA, and accomplishment of life habits was documented in an interview based on the LIFE-H questionnaire. Satisfaction with JACO and psychosocial impacts of its use were measured with validated questionnaires, namely the QUEST and the PIADS-10. Impacts of JACO on family caregivers were documented with a validated questionnaire, the CATOM. Descriptive statistics were used to report the results.

RESULTS

Seven users and five caregivers were recruited. One user had expenses related to JACO in the past two months. Users had a better upper extremity performance with JACO than without it and they used their robotic arm to accomplish certain life habits. Most users were satisfied with JACO and the psychosocial impacts were positive. Impacts on family caregivers were slight.

CONCLUSIONS

JACO increased performance in manipulation and facilitated the accomplishment of certain life habits. Users' increased participation in their life habits may slightly decrease the amount of caregiver assistance required. Future studies are needed to clarify its economic potential, its impact on caregivers' burden, including paid caregivers, and the variability in the tasks performed using JACO. Implications for Rehabilitation The use of JACO may have positive impacts on its users in terms of upper extremity performance, accomplishment of life habits, satisfaction with the device and psychosocial impacts. More research is needed to quantify more accurately the economic potential of the long-term use of JACO, to explore the factors related to the variability in the tasks performed using JACO, and to clarify the impact of JACO on caregivers' burden, including paid caregivers.

Temperature Dependence of the Optical Absorption Edge in Indium Phosphide

Optical bandgap thermometry is a new method for measuring the temperature of semiconductor substrates. In this method, the temperature of the substrate is inferred from the wavelength of the onset of transparency of the substrate which is a measure of its bandgap. Common configurations of this technique are diffuse reflectance and transmittance. In order to calibrate these spectra to substrate temperature and to better understand the temperature dependence of the absorption edge, the transmittance spectra of semi-insulating InP:Fe and n-type InP:S substrates have been measured as a function of temperature in a tube. The width of the absorption edge (Urbach parameter) is found to increase linearly with temperature from 8.7 meV at room temperature to 15.7 meV at 595°C for semi-insulating InP:Fe while it remains independent of temperature at a value of about 21.5 meV for heavily doped (6.5×1018 cm−3) InP:S. For InP:Fe, the temperature dependent part of the width is smaller than predicted by the standard theory where the width of the edge is proportional to the phonon population. The values of the Urbach parameter for InP:Fe are higher than those of semi-insulating GaAs which is attributed to the higher ionicity of InP.

The first preclinical pharmacotoxicological safety assessment of CGS 35601, a triple vasopeptidase inhibitor, in chronically instrumented, conscious, and unrestrained spontaneously hypertensive rats

CGS 35601 is a triple vasopeptidase inhibitor (VPI) of angiotensin-converting enzyme, neutral endopeptidase, and endothelin-converting enzyme-1 with respective IC50 values of 22, 2, and 55 nM. We characterized the safety profile and toxicity of escalating doses of CGS 35601 over a 20-day period in chronically instrumented, unrestrained, conscious, male, spontaneously hypertensive rats (SHR). Once instrumented with an arterial catheter, the SHR were placed in metabolic cages allowing daily assessment of hemodynamics and blood sampling for biochemical and hematological measurements. After a 7-day stabilization period, the SHR were divided into 2 groups: Gr. 1, (n = 13 to 18) receiving CGS 35601 at 0.01, 0.1, 1 and 5 mg kg(-1) day(-1) (continuous i.a. infusion) for 5 consecutive days/dose, followed by a 5-day washout; and Gr. 2, (n = 10) receiving vehicle (saline). The highest dose of CGS 35601 dose-dependently reduced MABP from 156 +/- 4 up to 94 +/- 5 mm Hg, whereas heart rate, metabolic, electrolytic, and hematological profiles, growth, diuresis, and renal activity were unaffected, and no hepatic or liver toxicities were observed. These results suggest that this novel triple VPI presents no safety concerns at this stage and may become of interest for the treatment of hypertension and other cardiovascular disorders. Long-term chronic experiments are needed to assess possible angioedema and increases in vascular permeability.

Triple VPI CGS 35601 reduces high blood pressure in low-renin, high-salt Dahl salt-sensitive rats

We previously reported that CGS 35601, a potent triple inhibitor of angiotensin-converting enzyme, neutral endopeptidase, and endothelin-converting enzyme 1, completely normalized mean arterial blood pressure (MABP) in 36-week-old spontaneously hypertensive rats, a normal renin model. The aim of the present study was to determine the effects of this triple vasopeptidase inhibitor (VPI) on the hemodynamic profile of instrumented, conscious, and unrestrained Dahl salt-sensitive (DSS) rats, a gene-prone, high-salt diet-induced low-renin hypertension model. Male DSS rats (mean weight [+/-SEM], 385 +/- 10 g) were fed a normal diet (Group 1) or a high-salt diet (Groups 2 and 3; 8% NaCl in food) for 6 weeks and then instrumented with a carotid catheter and placed individually in metabolic cages for 30 days. The hemodynamic, hematological, and biochemical profiles were assessed daily. Dose-dependent treatment started after a 7-day stabilization period in Groups 1 and 2 (vehicle dosage, 250 microl/hr) and Group 3 (CGS 35601 dosages of 0.1, 1, and 5 mg/kg/day for 6 days per dose by means of constant intra-arterial infusion), followed by a 5-day washout period. Two additional groups included normotensive Wistar rats (Group 4) and DSS rats that received a double high-salt solid (8% NaCl) and liquid (1% NaCl) diet (Group 5). The MABP in rats receiving CGS 35601 decreased in a dose-dependent fashion toward the baseline level observed in DSS rats receiving a normal diet. The heart rate was unaffected. The hemodynamic profile returned to normal during the washout period. This novel triple VPI is a potent and effective antihypertensive agent with a safe short-term profile that may be of interest for treating hypertension and other cardiovascular diseases. Other hypertensive rat models are being tested.

The hemodynamic and metabolic profiles of Zucker diabetic fatty rats treated with a single molecule triple vasopeptidase inhibitor, CGS 35601

CGS 35601 is a triple vasopeptidase inhibitor (VPI) of angiotensin converting enzyme (ACE), neutral endopeptidase (NEP), and endothelin (ET) converting enzyme-1 (ECE-1), with respective IC(50) values of 22, 2, and 55 nM. The aim of the present study was to establish the hemodynamic profile of Zucker diabetic fatty (Zdf)-Fatty rats, a high-fat diet gene-prone model developing spontaneous Type 2 diabetes (T2D) and the effects of CGS 35601. Male Zdf-Fatty (14 weeks, n = 17-23), Zdf-Lean (14 weeks, n = 8-10), and Wistar (14 weeks, n = 9-10) rats on distinct diets were implanted with a catheter in the left carotid and placed individually in a metabolic cage for 30 days. The hemodynamic profile and some metabolic biomarkers were assessed daily. After a 7-day stabilization period, the Zdf-Fatty rats were divided into two groups: Group 1, controls (n = 7-10) receiving vehicle-saline (250 microl/hr) and Group 2, (n = 10-13) receiving increasing doses of CGS 35601 (0.1, 1, and 5 mg/kg/day x 6 days each, intra-arterially) followed by a 5-day washout period. Mean arterial blood pressure (MABP) of young Zdf-Fatty rats was compared with age-matched Zdf-Lean and Wistar rats, which were found similar. MABP decreased by 5.9% (from baseline at 102 +/- 5 to 96 +/- 4 mmHg), 12.7% (to 89 +/- 6 mmHg) and 21.6% (to 80 +/- 4 mmHg), at 0.1, 1, and 5 mg/kg/day, respectively, in CGS 35601-treated Zdf-Fatty rats. Systolic and diastolic blood pressures were similarly reduced. The heart rate was not affected. Hyperglycemic status and insulin-resistance were not modulated by short-term treatment. CGS 35601 presented an excellent short-term safety profile. This novel molecule and class of VPI may be of interest for lowering vascular tone. Further long-term studies, once cardiovascular and renal complications have developed in this T2D rat model are warranted to define the efficacy of this class of VPI.

Profiling biochemical and hemodynamic markers using chronically instrumented, conscious and unrestrained rats undergoing severe, acute controlled hemorrhagic hypovolemic shock as an integrated in-vivo model system to assess new blood substitutes

The aim of the present study was to assess several biochemical and physiological endpoint parameters alongside controlled hemorrhagic and recovery phases of chronically instrumented, conscious and unrestrained healthy rats. Male Sprague-Dawley rats (12-14 weeks; 430+/-20 g; n=22-18) were instrumented with a saline-perfused femoral arterial catheter and placed individually in a metabolic cage for up to 20 days, allowing instant assessments of the hemodynamic profile and blood and urine sampling for hematological profile and biochemical measurements to assess hepatic, renal and metabolic functions. In addition, body weight, food and water intake, and diuresis were monitored daily. After a 7-day stabilization period, the rats underwent severe and acute hemorrhagic shock (HS) (removal of 50% of total circulating blood volume), kept in hypovolemic shock for an ischemic period of 50 min and then resuscitated over 10 min. Gr. 1 was re-infused with autologous shed blood (AB; n=10) whereas Gr. 2 was infused 1:1 with a solution of sterile saline-albumin (SA; 7% w/v) (n=8-12). Ischemic rats recovered much more rapidly following AB re-infusion than those receiving SA. Normal hemodynamic and biochemical profiles were re-established after 24 h. Depressed blood pressure lasted 4-5 days in SA rats. The hematological profile in the SA resuscitated rats was even more drastically affected. Circulating plasma concentrations of hemoglobin (-40%), hematocrit (-50%), RBC (-40%) and platelets (-41%) counts were still severely decreased 24 h after the acute ischemic event whereas WBC counts increased 2.2-fold by day 4. It took 5-9 days for these profiles to normalize after ischemia-reperfusion with SA. Diuresis increased in both groups (by 45+/-7% on day 1) but presented distinct electrolytic profiles. Hepatic and renal functions were normal in AB rats whereas altered in SA rats. The present set of experiments enabled us to validate a model of HS in conscious rats and the use of an integrated in vivo platform as a valuable tool to characterize HS-induced stress and to test new classes of blood substitutes in real time, post-event, over days.

Hemodynamic ischemic stroke during carotid endarterectomy: an appraisal of risk and cerebral protection

PURPOSE

The purpose of this study was to validate the commonly accepted indicators of risk of ischemic stroke that indicate the necessity for cerebral protection during carotid endarterectomy (CEA), and to examine the efficacy of high-dose thiopentone sodium (thiopental) as a cerebral protection method in patients who are at high risk of intraoperative ischemic stroke.

METHOD

In a prospective study of 37 CEAs performed for symptomatic stenosis > 70%, functional and clinical indicators of risk of ischemic stroke during carotid cross-clamping were identified. Functional indicators of risk were the development of ischemic electro-encephalogram (EEG) changes and stump pressure < 25 mm Hg. Clinical indicators of risk were previous ischemic hemispheric stroke and severe bilateral disease. These indicators were correlated in all patients, some of whom had two or three coexisting indicators of risk. The EEG and stump pressure were monitored continuously during carotid occlusion in all operations. Carotid occlusion times were recorded. Intraluminal shunting was eliminated in favor of high-dose thiopental cerebral protection in all patients. Neurologic outcome was deemed to measure the efficacy of thiopental protection in patients who are identified to be at risk and, hence, in need of cerebral protection. The validity of the indicators used to identify risk of ischemic stroke during CEA was assessed.

RESULTS

The absolute stroke risk was found to be 29.7% for the whole group (37 patients) and 57.9% in 19 patients who had commonly accepted indications for protective shunting. The correlation of ischemic EEG changes with stump pressure < 25 mm Hg was only 27.3%, whereas the expected correlation based on well-documented reports in the literature was 100%. The lack of correlation may have been related to the prevention of ischemic EEG changes by thiopental. There were no neurologic deficits in the series.

CONCLUSIONS

The absence of neurologic deficit in the study indicated that thiopental protection was effective in preventing ischemic stroke in high-risk patients and safely replaced intraluminal shunting.

Evaluation of Interventions for Prevention of Back, Neck, and Shoulder Disorders in Three Occupational Groups

An epidemiologic study was carried out in order to evaluate the effects of prevention programs at the workplace aimed at reducing back, neck, and shoulder morbidity among active workers. The intervention group included 275 workers in three occupational subgroups: hospital workers, warehouse workers, and office workers. The control group included 250 workers as comparable as possible to the intervention group. Comparisons were made, according to one-year changes in morbidity scores, for low back, upper back, neck, and shoulder disorders separately. An overall measure was also used. The one-year change in the overall measure was significantly different between the intervention group and the control group, indicating a positive effect of the prevention programs. Positive effects were stronger for some sites of pain and some occupational groups.

Pseudoaneurysm of the proper hepatic artery with duodenal fistula appearing as a late complication of blunt abdominal trauma

Posttraumatic pseudoaneurysms of the hepatic artery are rare and usually occur as a complication of open abdominal trauma. Even less common is the coexisting presence of enteric fistulization. We report a patient with upper gastrointestinal hemorrhage occurring 3 years after blunt abdominal trauma resulting from a pseudoaneurysm of the proper hepatic artery with duodenal fistulization. The patient was treated successfully by ligation of the proper hepatic artery and closure of the duodenal opening.

Antimicrobial susceptibility of Streptococcus suis isolates

The antimicrobial activities of penicillin (PEN), ampicillin (AMP), cephalothin (CT), trimethoprim-sulphamethoxazole (TMP-SMX), streptomycin (STM), and gentamicin (GM) against 122 representative strains of Streptococcus suis, were compared by the agar dilution procedure. The current US National Committee for Clinical Laboratory Standards (NCCLS) breakpoints for non-enterococcal streptococci were used for PEN, AMP, CT, and TMP-SMX. Overall, 50% of strains were not fully susceptible to PEN, whereas these percentages for AMP and CT were 9% and 6% respectively. One strain was resistant to TMP-SMX. High-level GM resistance could not be detected, but more than 46% of strains were highly resistant to STM (MIC > 2000 mg l-1). This high percentage of resistance to STM precludes the use of this aminoglycoside-penicillin combination as empiric therapy in severe S. suis infections. These results should prompt microbiology laboratories to carry out antimicrobial susceptibility tests on a routine basis on S. suis isolates.

Molecular analysis of isolates of Streptococcus suis capsular type 2 by restriction-endonuclease-digested DNA separated on SDS-PAGE and by hybridization with an rDNA probe

This study was undertaken to assess the discriminatory value of restriction endonuclease (RE) digestion patterns of Streptococcus suis chromosomal DNA using polyacrylamide gel electrophoresis (SDS-PAGE) and DNA-rDNA hybridization. For the RE digestion patterns, DNAs were digested separately with the enzymes BamHI and BglII and the resultant fragments were separated by SDS-PAGE. An Escherichia coli rDNA probe derived from pKK3535 was used for the hybridization. Twenty-three S. suis capsular type 2 isolates recovered from diseased and clinically healthy pigs, from a human case, and from a cow were compared in this study. The majority of isolates associated with septicaemia belonged to one restriction endonuclease analysis (REA) profile group. Isolates associated with pneumonia belonged either to the REA profile group of isolates associated with septicaemia or to a second REA profile group. The REA profiles of isolates from clinically healthy animals were more heterogeneous. The REA profile of the type 2 reference strain, S735, which was originally isolated from a pig, was very different from those of the porcine and bovine isolates but similar to the profile of the human isolate. The profiles obtained after rDNA hybridization were more homogeneous. Although different patterns were detected in the 23 isolates, there was no correlation between the source of the isolate and the patterns observed with this technique.

Studies on a murine model for evaluation of virulence of Streptococcus suis capsular type 2 isolates

Five different parameters, time of incubation of the culture, type of culture medium, inoculum, strain of inbred mice, and age of mice, were tested using the LD50 technique to standardize a murine model for the evaluation of the virulence of Streptococcus suis capsular type 2 isolates. A model using 28 day-old mice belonging to CF1 strain appeared to give the best results. The inoculum size was the parameter most influencing the 50% lethal dose obtained with mice. Inoculation with 1-ml volume of a bacterial suspension instead of 0.1 or 0.5 ml decreased the LD50. The standardized model was used to evaluate the virulence of some isolates of known pathogenicity for pigs. The minimum lethal dose was used in the model and it appeared that the virulence of Streptococcus suis capsular type 2 isolates can be measured from highly virulent to totally avirulent.

Effect of neonatal degranulation on the morphological development of rat CA3 pyramidal neurons: inductive role of mossy fibers on the formation of thorny excrescences

Intracellular peroxidase injections were made on CA3 pyramidal neurons from slices obtained from 3-60 day old control and experimental rats. Experimental rats had been irradiated at birth with gamma-rays to destroy the granule cells of the fascia dentata. Neonatal gamma-ray irradiation induced a clear cut reduction of the total number of granule cells (80% decrease at P60) and mossy fibers as revealed by Nissl and Timm stains. The number of branching points and segments, total dendritic length, and density of dendritic spines in the stratum radiatum and stratum oriens on CA3 pyramidal cells were not significantly different between control and irradiated rats. To quantify the development of thorny excrescences we measured the number and total area of the thorny excrescences per neuron at different stages of development. gamma-Ray irradiation induced a reduction in the number and total area of thorny excrescences. This effect was readily apparent by postnatal day (P) 12, and a reduction of 70% in the total area was observed at P30. In conclusion, gamma-ray irradiation destroys the majority of granule cells and induces a reduction in the development of thorny excrescences. Our data strongly suggest that this effect is directly caused by the lack of mossy fibers rather than by the irradiation itself since other parameters (i.e., the number of segments and branching points, density of non-mossy spines, and total dendritic length) were not affected. Therefore, we suggest that mossy fibers play an inductive role in the formation of thorny excrescences.

Distribution of Streptococcus suis capsular types in Quebec and western Canada

Of a total of 561 isolates of Streptococcus suis recovered from various tissues of diseased pigs, 464 were from veterinary laboratories in Quebec and 97 were from western Canada, particularly Alberta (84). Almost 83% of all these isolates belonged to the 23 known S. suis capsular types. There was no marked difference between the two groups of isolates. Capsular type 2 was the most prevalent and represented 32% of all isolates. The other important capsular types were, in decreasing order, 3, 1/2, 8 and 4. Lungs, brain, and meninges were the source of the majority of isolates. More than 40% of all S. suis isolates were found in pure culture. The number of isolations of this microorganism was higher in piglets aged five to eight weeks than in any other age group.

Characterization of six new capsular types (23 through 28) of Streptococcus suis

Six new capsular types of Streptococcus suis (types 23 to 28) are described. All reference strains were isolated from diseased pigs and were morphologically and biochemically similar to previously described capsular types 1 to 22. Clear and specific reactions were obtained for each of the new capsular types with three different typing techniques; no cross-reactions were detected among them or with other S. suis capsular types. Their capsular material presented similar ultrastructural characteristics, as shown by electron microscopy, and fimbriae similar to those described for other capsular types of S. suis were observed. When untypeable field isolates were tested with antisera raised against the six new capsular types, capsular type 23 appeared to be the most prevalent, representing more than 50% of all these isolates. Most isolates were recovered from cases of pneumonia, septicemia, and meningitis. Presumptive biochemical identification described for S. suis capsular types 1 to 22 may also be used for capsular types 23 to 28.

Effects of neonatal gamma-ray irradiation on rat hippocampus--I. Postnatal maturation of hippocampal cells

The axons of dentate granule cells, the mossy fibres, establish synaptic contacts with the thorny excrescences of the apical dendrite of CA3 pyramidal neurons. Dentate granule granule cells develop postnatally in rats, whereas the CA3 pyramidal cells are generated before birth. In the present studies, using unilateral neonatal gamma-ray irradiation to destroy the granule cells in one hemisphere, we have studied the effect of mossy fibre deprivation on the development of their targets. We show that such "degranulation" prevents the normal development of giant thorny excrescences, suggesting that the development of thorny excrescences in CA3 pyramidal neurons is under the control of mossy fibres. In contrast, irradiation of the hippocampus of the neonatal rat does not affect the development of the dendritic arborization of CA3 pyramidal cells and their non-mossy dendritic spines.

Isolation and characterization of Streptococcus suis capsular types 9-22

The incidence and biochemical patterns of Streptococcus suis capsular types 9-22 are presented. Of 148 untypeable (with types 1-8 antisera) isolates of S. suis recovered from diseased pigs, 10% were not capsulated. Of the remaining 134 isolates, only 53% belonged to capsular types 9-22; capsular types 22 and 9 were the most prevalent, representing 19% and 13%, respectively. Capsular type 15 (de Moor's group T Streptococcus) is reported here for the first time in North America since it was described in 1963 in Europe. Of 188 untypeable isolates recovered from clinically healthy pigs, 25% were noncapsulated. Of the remaining 141 isolates, 90% belonged to the new capsular types, and 87% were identified as 1 of 4 types: 17, 18, 19, and 21. Capsular types 12 and 20 were not detected among the Canadian isolates. Almost half of strains were arginine dihydrolase-negative, and 45% fermented mannitol, which is seldom a positive test with capsular types 1-8. Although some strains were negative with salicin or trehalose, none were negative for both sugars. Only 54% of isolates tested with 1 rapid multitest system were correctly identified as S. suis. A tentative biochemical profile that might be used with a microplate identification system is also presented. Biochemical identification using the conventional system instead of the rapid multitest system is preferable.

Effects of kainic acid-induced seizures and ischemia on c-fos-like proteins in rat brain

We have analyzed the brain pattern and time-course of c-fos-like proteins expression in kainic acid-induced seizures in the rat. C-fos-like immunoreactivity increased initially in the hippocampus, notably in the dentate gyrus, at the time of the first limbic motor seizure (90 min after kainate). C-fos-like labelling progressively involved different structures of the limbic system when the rats manifested a permanent epileptic state (3-6 h). The labelling was still conspicuous 12 h after kainate treatment and progressively declined to reach control levels 48 h after kainate. This time-course is similar to that produced by kainic acid on 2-deoxyglucose consumption and correlates with the electrographic changes previously described, supporting the idea that c-fos-like immunostaining may provide a useful marker of neuronal activity, with a cellular resolution. Since anoxic-ischemic treatment produces a very slight and transient increase in c-fos-like immunostaining restricted to the fascia dentata, c-fos-like expression is seizure-related and not due to a local hypoxia or ischemia.

Does the radial arterial line degrade the performance of a pulse oximeter?

The presence of radial arterial lines may diminish distal digital perfusion. Using a pair of pulse oximeters on the index fingers of cannulated and noncannulated arms the saturation and oximeter pulse strength were assessed. Three hundred paired measurements in fifty consecutive Intensive Care patients were undertaken more than two hours after cannula insertion. The pulse strength was 19.7 (SD 6.1) and 19.7 (SD 5.7) on the cannulated and noncannulated sides while the saturation was 97.3 (SD 2.3) and 97.1 (SD 2.4) respectively. These differences are not clinically important and the study demonstrates that reliable pulse oximetry measurements may be made distal to a radial artery cannula. It is recommended that in each individual the placement of the sensor be such as to ensure the best signal and the most stable saturation readings.

Streptococcus suis infection in swine. A sixteen month study

A total of 349 isolates of Streptococcus suis retrieved from different tissues from diseased pigs were examined in this study. Only 48% of them could be categorized as one of serotypes 1 to 8 and 1/2. Among typable isolates, serotype 2 was the most prevalent (23%), followed by serotype 3 (10%). The majority of all isolates originated from lungs, meninges/brain, and multiple tissues. Forty-one percent of typable isolates and 33% of untypable isolates were retrieved in pure culture. Other isolates were found in conjunction with Pasteurella multocida, Escherichia coli, Actinobacillus pleuropneumoniae, Actinomyces pyogenes, and other streptococci. Typable S. suis isolates were more frequently isolated from pigs between five and ten weeks of age, while untypable isolates were mostly found in animals aged more than 24 weeks. No obvious monthly and/or seasonal variation of the prevalence of isolation of S. suis could be detected.

Hippocampal damage induced by ischemia and intra-amygdaloid kainate injection: effect on N-methyl-D-aspartate, N-(1-[2-thienyl]cyclohexyl)piperidine and glycine binding sites

The N-methyl-D-aspartate receptor channel-complex is widely distributed in the hippocampus, particularly in the CA1 region, in the terminal field of CA3 pyramidal axons and in the fascia dentata, in the terminal field of the perforant pathway. In the present study, we have examined, in the rat, the effect of specific lesions of various neuronal populations of the hippocampus on the distribution of several markers of the N-methyl-D-aspartate receptor-channel complex. Anoxic-ischemic treatment produced a destruction of CA1 pyramidal cells (postsynaptic element): this was associated with a 50% loss of N-methyl-D-aspartate, glycine and N-(1-phenylcyclohexyl)piperidine binding sites. In contrast, the destruction of CA3 pyramidal cells and their axons (presynaptic element) by kainate treatment did not induce significant changes in the density of binding sites. The present results therefore strongly support an exclusively postsynaptic localization of the N-methyl-D-aspartate receptor-channel complex in CA1; the possibility of a localization of the remaining binding sites on glial cells or interneurons is discussed. In the molecular layer of the fascia dentata, the anoxic-ischemic treatment produced a partial destruction of the median perforant pathway (presynaptic element) associated with a decrease in the density of N-methyl-D-aspartate, N-(1-[2-thienyl]cyclohexyl)piperidine and glycine binding sites; this suggests that, in contrast to CA1, in the molecular layer of the fascia dentata, N-methyl-D-aspartate receptor-binding sites are located both pre- and postsynaptically.

[Predictive value of preoperative acidity tests in ulcer recurrence after supraselective vagotomy]

The authors have analysed the predictive value of the basal and peak gastric acidity levels, measured preoperatively, in a series of 27 supraselective vagotomies. They recommend care in the choice of this operation for hypersecretors and they propose criteria for the preoperative selection of the candidates. They suggest determination of the preoperative basal gastric acidity level and a cimetidine suppression test to identify patients at high risk for recurrence of the ulcer.