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Background: It is estimated that approximately 50% of individuals who incur right-hemisphere damage (RHD) have subsequent communication disorders. Lexical-semantic, discourse, prosodic, and pragmatic deficits have been reported following RHD, but the co-occurrence of these deficits within the same individual has not yet been systematically investigated. Therefore clinical profiles of communication impairments in individuals with RHD still have to be identified and described in order to appreciate their communication impairment and provide strategies for rehabilitation.Aims: The goal of the present study was to explore the clinical profiles of communication impairments subsequent to a right hemisphere lesion.Methods and Procedures: A total of 28 French-speaking individuals with a right-hemisphere lesion were evaluated using the Protocole MEC (Joanette, Ska, & Cote, 2004), a normalised battery allowing the assessment of communication deficits after RHD. A hierarchical cluster analysis was used to group participants according to similarities in their results on the 14 tasks.Outcomes and Results: Four subgroups of RHD individuals were identified on the basis of the overall similarities of performance on the 14 tasks of the Protocole MEC. Participants in the first cluster showed impairments in all four language components evaluated, whereas the second cluster of participants was also impaired in prosodic, lexical-semantic, and pragmatic abilities, but was characterised by a relative preservation of discourse abilities. The third cluster of participants did not show any abnormal results. Finally, two individuals were mainly characterised by some lexical-semantic deficits.Conclusions: The Protocole MEC used in conjunction with a cluster analysis provided a first step towards the identification of communication impairment profiles among the population of individuals with RHD. In the present study it was not possible to clearly identify the relationship between a given profile and factors such as lesion site, age, or education. Incidence of communication impairments was estimated to be higher in a rehabilitation centre setting than the generally accepted 50% in the literature. [ABSTRACT FROM AUTHOR]

The inaugural Canadian Conferences on Translational Geroscience were held as 2 complementary sessions in October and November 2023. The conferences explored the profound interplay between the biology of aging, social determinants of health, the potential societal impact of geroscience, and the maintenance of health in aging individuals. Although topics such as cellular senescence, molecular and genetic determinants of aging, and prevention of chronic disease were addressed, the conferences went on to emphasize practical applications for enhancing older people's quality of life. This article summarizes the proceeding and underscores the synergy between clinical and fundamental studies. Future directions highlight national and global collaborations and the crucial integration of early-career investigators. This work charts a course for a national framework for continued innovation and advancement in translational geroscience in Canada., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Knowledge translation (KT) is a key competency for trainees (graduate students and post-doctoral fellows), the new generation of researchers who must learn how to synthesize, disseminate, exchange, and ethically apply knowledge to improve patient and health system services, products, and outcomes. KT training is a key enabler to support KT competency development. Yet, there is a dearth of research on the design, delivery, and evaluation of KT training for trainees., Methods: The study applied a QUAN(qual) mixed methods approach with an embedded experimental model design. A heart and lung patient was also recruited to participate as a partner and researcher in the study. A multi-faceted KT intervention for trainees was designed, delivered, and evaluated. Data were collected using surveys and focus groups. Quantitative data were analyzed using descriptive and inferential statistics in R Studio and MS Excel. Qualitative data were analyzed in NVivo using thematic analysis., Results: Participation in each KT intervention varied, with 8-42 participants attending KT webinars, 61 attendees in the Three Minute Thesis (3MT) Competition Heat, and 31 participants in the Patient & Public Forum. In total, 27 trainees and 4 faculty participated in at least one of the KT webinars. Trainee participants reported satisfaction, as well as statistically significant increases in 10/13 KT competencies after receiving one or more components of the KT intervention. Additionally, participating faculty, patients, and the public were satisfied with the intervention components they participated in. Several challenges and facilitators were also identified to improve the KT intervention., Conclusions: The KT intervention is a promising initiative that can be adopted and adapted across various post-secondary settings to support trainees' competency development in KT. This evaluation demonstrates that trainees will respond to opportunities for KT training and that capacity for KT competencies can be advanced through a multi-faceted intervention that involves trainees, faculty, patients, and health system collaborators in its design and delivery. This evaluation study contributes the design and results of a novel KT intervention for multi-stakeholders., Trial Registration: N/A., (© 2023. The Author(s).)

Multiple psychosocial interventions to treat ADHD symptoms have been developed and empirically tested. However, no clear recommendations exist regarding the utilization of these interventions for treating core ADHD symptoms across different populations. The objective of this systematic review and meta-analysis by the CADDRA Guidelines work Group was to generate such recommendations, using recent evidence. Randomized controlled trials (RCT) and meta-analyses (MA) from 2010 to 13 February 2020 were searched in PubMed, PsycINFO, EMBASE, EBM Reviews and CINAHL. Studies of populations with significant levels of comorbidities were excluded. Thirty-one studies were included in the qualitative synthesis (22 RCT, 9 MA) and 24 studies (19 RCT, 5 MA) were included in the quantitative synthesis. Using three-level meta-analyses to pool results of multiple observations from each RCT, as well as four-level meta-analyses to pool results from multiples outcomes and multiple studies of each MA, we generated recommendations using the GRADE approach for: Cognitive Behavioral Therapy; Physical Exercise and Mind-Body intervention; Caregiver intervention; School-based and Executive intervention; and other interventions for core ADHD symptoms across Preschooler, Child, Adolescent and Adult populations. The evidence supports a recommendation for Cognitive Behavioral Therapy for adults and Caregiver intervention for Children, but not for preschoolers. There were not enough data to provide recommendations for the other types of psychosocial interventions. Our results are in line with previous meta-analytic assessments; however, they provide a more in-depth assessment of the effect of psychosocial intervention on core ADHD symptoms., Competing Interests: The authors declare no conflict of interest.

The use of growth-promoting antibiotics in livestock faces increasing scrutiny and opposition due to concerns about the increased occurrence of antibiotic-resistant bacteria. Alternative solutions are being sought, and plants of Lamiaceae may provide an alternative to synthetic antibiotics in animal nutrition. In this study, we extracted essential oil from Monarda didyma , a member of the Lamiaceae family. We examined the chemical composition of the essential oil and then evaluated the antibacterial, antioxidant, and anti-inflammatory activities of M. didyma essential oil and its main compounds in vitro . We then evaluated the effectiveness of M. didyma essential oil in regard to growth performance, feed efficiency, and mortality in both mice and broilers. Carvacrol (49.03%) was the dominant compound in the essential oil extracts. M. didyma essential oil demonstrated antibacterial properties against Escherichia coli (MIC = 87 µg·mL -1 ), Staphylococcus aureus (MIC = 47 µg·mL -1 ), and Clostridium perfringens (MIC = 35 µg·mL -1 ). Supplementing the diet of mice with essential oil at a concentration of 0.1% significantly increased body weight (+5.4%) and feed efficiency (+18.85%). In broilers, M. didyma essential oil significantly improved body weight gain (2.64%). Our results suggest that adding M. didyma essential oil to the diet of broilers offers a potential substitute for antibiotic growth promoters.

Five batches of resin from the Pili tree (Canarium ovatum Engl.) were distilled, and their essential oils and hydrosols were analyzed by gas chromatography. The oils, obtained in yields of 13.4-19.7 % v/m, featured α-phellandrene in high proportions (50-65 %), alongside limonene, β-phellandrene and para-cymene. Chiral GC analysis confirmed that both phellandrenes were in fact >95 % (S)-(+) enantiomers, while the other monoterpenes featured less pronounced enantiomeric excesses. The hydrosols were rich in α-phellandrene oxidation products including cis-α-phellandrene epoxide and a series of para-menth-5-ene-1,2-diol isomers. Both essential oils and hydrosols were tested for their antibacterial activity against Escherichia coli and Staphylococcus aureus and exhibited MIC 90 of less than 5 and 0.5 mg/mL of total volatiles, respectively. The essential oil features some potential as a source of readily available natural (S)-(+)-α-phellandrene., (© 2020 Wiley-VHCA AG, Zurich, Switzerland.)

Objectives: Combination antiretroviral therapy has largely restored the lifespan of persons living with HIV. Data suggest early comorbidities of aging in this population. Past studies focused on men; limited data exist regarding the prevalence of dyslipidaemia in women living with HIV (WLWH). We investigated the prevalence of cardiometabolic abnormalities among WLWH and HIV-negative women in the Children and Women: Antiretrovirals and Markers of Aging (CARMA) cohort, and their relationships to cellular aging markers., Methods: We conducted a cross-sectional analysis of nonpregnant female patients (156 WLWH and 133 HIV-negative controls, aged 12-69 years) enrolled in CARMA between 2013 and 2017. The Framingham risk score (FRS) and the prevalences of hypertension, diabetes, metabolic syndrome and dyslipideamia were determined using self-report, anthropometrics, chart review and laboratory data. Cellular aging was determined by assessing leukocyte telomere length and blood mitochondrial DNA content. Diagnoses were based on current Canadian guidelines and definitions., Results: HIV-infected status was associated with dyslipidaemia [odds ratio (OR) 2.89; 95% confidence interval (CI) 1.69-5.01], but not diabetes, higher FRS, hypertension or metabolic syndrome. The median age was 43.5 [interquartile range (IQR) 36.8-50.9] years in WLWH and 46.2 (IQR 30.3-54.9) years in HIV-negative controls. WLWH were less likely to be menopausal or use alcohol, and more often had hepatitis C virus infection or a current or past smoking history. Lower mitochondrial DNA content was associated with metabolic syndrome; no other associations were noted between cardiometabolic abnormalities and markers of cellular aging., Conclusions: Despite their relatively young age, almost two-thirds of WLWH had dyslipidaemia, a significantly greater proportion than in controls. Strategies to address dyslipidaemia and decrease smoking rates may improve long-term outcomes among WLWH., (© 2020 British HIV Association.)

The chemical composition of Tussilago farfara L. essential oil from the Saguenay-Lac-St-Jean region of Quebec, Canada was analyzed by gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS), and the antibacterial activity of the oil was tested against Escherichia coli and Staphylococcus aureus . Forty-five (45) compounds were identified from the GC profile. The main components were 1-nonene (40.1%), α-phellandrene (26.0%) and ρ-cymene (6.6%). The essential oil demonstrated antibacterial activity against E . coli (MIC 50 = 468 µg·mL -1 ; MIC 90 = 6869 µg·mL -1 ) and S . aureus (MIC 50 = 368 µg·mL -1 ; MIC 90 = 773 µg·mL -1 ). Dodecanoic acid was found to be active against both bacteria having a MIC 50 and MIC 90 of 16.4 µg·mL -1 and 95 µg·mL -1 , respectively for E . coli and a MIC 50 and MIC 90 of 9.8 µg·mL -1 and 27.3 µg·mL -1 , respectively for S . aureus . In addition, 1-decene and (E) -cyclodecene were also found to be active against E . coli .

Purpose: Search for reliability and validity evidence for the Montreal Communication Evaluation Brief Battery (MEC B) for adults with right brain damage., Methods: Three hundred twenty-four healthy adults and 26 adults with right brain damage, aged 19-75 years, with two or more years of education were evaluated with MEC B. The MEC B Battery contains nine tasks that aim to evaluate communicative abilities as discourse, prosody, lexical-semantic and pragmatic process. Two sources of reliability evidence were used: internal consistency (Cronbach's alpha) and interrater reliability. Construct validity was evaluated comparing the Montreal Communication Evaluation Battery (MEC), expanded version and MEC B tasks., Results: Internal consistence was satisfactory and the interrater reliability was considered excellent, as were correlations between MEC Battery and MEC B Battery tasks., Conclusion: The MEC B Battery showed satisfactory reliability and validity evidences. It can be used as outcome measure of intervention programs and assist speech therapists to plan rehabilitation programs.

New options are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Balsacone C is a new dihydrochalcone extracted from Populus balsamifera that has been reported previously as being active against Staphylococcus aureus . Here, we evaluate the antibacterial activity of balsacone C against MRSA. Thirty-four (34) MRSA isolates were obtained from hospitalized patients; these isolates were then characterized for their resistance. Most of these MRSA (>85%) were resistant to penicillin, amoxicillin/clavulanic acid, ciprofloxacin, moxifloxacin, levofloxacin, clindamycin, erythromycin, and cefoxitin as well as being sensitive to linezolid, trimethoprim/sulfamethoxazole, rifampicin, and gentamicin. When tested against all MRSA isolates and various gram-positive bacteria, the antibacterial activity of balsacone C produced a MIC of 3-11.6 mg/mL. We observed no resistant isolates of MRSA (against balsacone C) even after 30 passages. Microscopy fluorescence showed that bacteria cell membrane integrity was compromised by low concentrations of balsacone C. Scanning electron microscope (SEM) confirmed balsacone C-provoked changes in the bacterial cell membrane and we find a dose-dependent release of DNA and proteins. This loss of cellular integrity leads to cell death and suggests a low potential for the development of spontaneous resistance., (Copyright © 2019 Côté, Pichette, Simard, Ouellette, Ripoll, Mihoub, Grimard and Legault.)

In Canada, about 6,000 youth are homeless every night, many of whom suffer from addiction and psychotic disorders. To facilitate the exit out of homelessness, access to care and to improve psychosis and addiction outcomes, a new intensive outreach intervention team (EQIIP SOL) was created in Montreal (2012). It offers intensive outreach services dedicated to homeless youth suffering from first episode psychosis and addiction (HYFEPA) in addition to an early psychosis intervention service (EIS) in collaboration with the Addiction Psychiatry Unit. Our aim is to describe the characteristics, clinical, functional and housing outcomes of HYFEPA followed by EQIIP SOL. This two years long prospective longitudinal study with all HYFEPA (n = 42) admitted to EQIIP SOL between 2012-2015 reports at multiple time points, clinical (CGI, GAF), functional (SOFAS, work/study, housing autonomy) and substance use disorder (DUS, AUS) outcomes and acute services use (hospitalizations, emergency room visits). We observed that, at baseline, HYFEPA showed poor prognostic factors (eg. cluster B personality, substance use disorders, legal problems, childhood trauma and lower education level). The majority reached housing stability after 6 months and their functioning and illness severity improved with time. This suggests that HYFEPA improve with an intensive outreach intervention team integrated to an EIS., (Copyright © 2019. Published by Elsevier B.V.)

Essentials Activated clotting factor X (FXa) acquires fibrinolytic cofactor function after cleavage by plasmin. FXa-mediated plasma fibrinolysis is enabled by active site modification blocking a second cleavage. FXa-directed oral anticoagulants (DOACs) alter FXa cleavage by plasmin. DOACs enhance FX-dependent fibrinolysis and plasmin generation by tissue plasminogen activator., Background: When bound to an anionic phospholipid-containing membrane, activated clotting factor X (FXa) is sequentially cleaved by plasmin from the intact form, FXaα, to FXaβ and then to Xa33/13. Tissue-type plasminogen activator (t-PA) produces plasmin and is the initiator of fibrinolysis. Both FXaβ and Xa33/13 enhance t-PA-mediated plasminogen activation. Although stable in experiments using purified proteins, Xa33/13 rapidly loses t-PA cofactor function in plasma. Bypassing this inhibition, covalent modification of the FXaα active site prevents Xa33/13 formation by plasmin, and the persistent FXaβ enhances plasma fibrinolysis. As the direct oral anticoagulants (DOACs) rivaroxaban and apixaban bind to the FXa active site, we hypothesized that they similarly modulate FXa fibrinolytic function., Methods: DOAC effects on fibrinolysis and the t-PA cofactor function of FXa were studied in patient plasma, normal pooled plasma and purified protein experiments by the use of light scattering, chromogenic assays, and immunoblots., Results: The plasma of patients taking rivaroxaban showed enhanced fibrinolysis correlating with FXaβ. In normal pooled plasma, the addition of rivaroxaban or apixaban also shortened fibrinolysis times. This was related to the cleavage product, FXaβ, which increased plasmin production by t-PA. It was confirmed that these results were not caused by DOACs affecting activated FXIII-mediated fibrin crosslinking, clot ultrastructure and thrombin-activatable fibrinolysis inhibitor activation in plasma., Conclusion: The current study suggests a previously unknown effect of DOACs on FXa in addition to their well-documented anticoagulant role. By enabling the t-PA cofactor function of FXaβ in plasma, DOACs also enhance fibrinolysis. This effect may broaden their therapeutic indications., (© 2018 International Society on Thrombosis and Haemostasis.)

Objectives: To determine if bone health is compromised in perinatally HIV-infected youth., Methods: We assessed BMC at the proximal femur, lumbar spine and total body using DXA in perinatally HIV-infected youth (n=31; 9-18y). Using pQCT, we assessed muscle CSA, total and cortical bone area, cortical BMD and thickness and strength strain index at the tibial shaft. Thirty and 18 participants returned at 12- and 24-months, respectively. We calculated age- and sex-specific z-scores for the HIV-infected youth using data from a healthy cohort (n=883; 9-18y)., Results: At baseline, height and MCSA were reduced in HIV-infected youth (-0.79 to -0.23, p<0.05). BMC z-scores adjusted for height and lean mass were lower than controls at all sites except the lumbar spine (-0.57 to -0.27, p<0.05). Bone area and strength z-scores were not different from zero after adjusting for tibial length and MCSA. In contrast, cortical BMD z-scores were greater in HIV-infected youth (0.46, p=0.011). Z-scores for all bone outcomes showed positive trends over time in HIV-infected youth., Conclusion: Although HIV infection may be associated with bone mass deficits during growth, bone geometry and strength appear adapted to muscle force. Further, deficits in bone mass may dissipate over time in this population.

Identifying natural barriers to movements of hosts associated with infectious diseases is essential for developing effective control strategies. Raccoon rabies variant (RRV) is a zoonosis of concern for humans because its main vector, the raccoon (Procyon lotor), is found near residential areas. In Québec, Canada, all cases of RRV found in raccoons since 2006 were detected on the eastern side of the Richelieu River, suggesting that this river acts as a barrier to gene flow and thus the potential for RRV to spread. The objectives of this study were to characterize the genetic structure of raccoon populations and assess the effect of the Richelieu River on the population structure in southern Québec, Canada. We also evaluated whether RRV spread potential differed between sex and at a larger spatial scale. Our analyses revealed a weak signal of genetic differentiation among individuals located on each side of the Richelieu River. At a larger spatial scale, genetic structuring was weak. Our results suggest that rivers might not always efficiently restrain raccoon movements and spread of RRV. We suggest that the difference in genetic structure found between sexes can be partly explained by male movements during the breeding season in winter, when ice bridges allow passage over most rivers in Québec.

The lack of standardized instruments to evaluate communication disorders related to the right hemisphere was verified. A new evaluation tool was developed: Protocole Montréal d'Evaluation de la Communication--Protocole MEC, adapted to Brazilian Portuguese--Bateria Montreal de Avaliação da Comunicação--Bateria MAC (Montreal Evaluation of Communication Battery). The purpose was to present stratified normative data by age and educational level, and to verify the reliability parameters of the MEC Battery. 300 individuals, between the ages of 19 and 75 years, and levels of formal education between 2 and 35 years, participated in this study. They were divided equally into six normative groups, according to three age categories (young adults, intermediary age, and seniors) and two educational levels (low and high). Two procedures were used to check reliability: Cronbach alpha and reliability between evaluators, Results were established at the 10th percentile, and an alert point per task for each normative group. Cronbach's alpha was, in general, between .70 and .90 and the average rate of agreement between evaluators varied from .62 to .94. Standards of age and education were established. The reliability of this instrument was verified. The psychometric legitimization of the MEC Battery will contribute to the diagnostic process for communicative disorders.

Background: an assessment instrument to evaluate communication impairment after right brain damage: the Montreal Communication Evaluation Battery, an adapted brazilian version of the original canadian instrument--Protocole Montréal d'Evaluation de la Communication. Instruments that evaluate discursive, pragmatic, lexical-semantic and prosodic impairments are important for the diagnosis of communication disorders which are present in approximately 50% of the individuals with right brain damage. Systematic studies of the communication profile after lesions on this side of the brain have been carried out only during the last two decades., Aim: to present the Montreal Communication Evaluation Battery to brazilian speech therapists., Conclusion: the described instrument is an useful tool in the clinic for assessing four processes related to the communicative and linguistic abilities: discursive, pragmatic-inferential, lexical-semantic and prosodic components. It is has been normalized, validated and its reliability has been confirmed. Although this instrument was developed and adapted for diagnosing communication disorders in individuals with right brain damage people, it can also be helpful in investigating communication sequels in traumatic brain injury, dementia, bilateral frontal lesions, left-brain damage, psychopathologies, such as schizophrenia, among others.

Introduction: A lesion of the right hemisphere of right-handers can result in verbal communication impairments. The recent development of theoretical frameworks with regard to discourse and pragmatic abilities, among others, now allows us to recognize and describe these impairments., Aim: To offer an overview of the verbal communication deficits that can be found in right-hemisphere-damaged individuals. These deficits can interfere, at different levels, with prosody, the semantic processing of words and discourse and pragmatic abilities., Development: Such impairments appear to be present in about half of right-hemisphere-damaged patients and, when present, can result in different clinical profiles. These deficits raise the question of their labeling and their relationship with aphasia., Conclusions: Given the evolution of the concept of language and the universal definition of aphasia, it is proposed that these deficits correspond to another manifestation of aphasia, thus challenging the idea that they are of a 'non-aphasic' nature.

Objectives: To compare the efficacy and safety of a nucleoside-sparing approach with a conventional highly active antiretroviral therapy (HAART) regimen in antiretroviral-experienced patients with prolonged viral suppression., Methods: Pilot study including 31 antiretroviral-experienced patients with HIV RNA <80 copies/mL. Subjects were randomly assigned to lopinavir/ritonavir (LPV/rtv) 400/100 mg BID plus nevirapine (NVP) 200 mg BID (NVP group, n = 16) or LPV/rtv plus the 2 previous NRTIs (NRTI group, n = 15). The primary endpoint was the percentage of subjects who maintained viral suppression at week 48. Changes in lipid metabolism, mitochondrial parameters, and LPV trough levels were also assessed., Results: All patients maintained viral suppression after 48 weeks. No subject discontinued therapy because of adverse events. HDL cholesterol increased by 28% at week 24 (P < 0.0001) and 10% after 48 weeks of follow-up (P = 0.319) in the NVP group. In the NRTI group, LDL cholesterol increased by 14% at week 48 (P = 0.076). Mitochondrial DNA/nuclear DNA ratio and mitochondrial respiratory chain complex IV activity showed a trend toward increasing in the NVP group. Mean (SD) LPV trough levels were 6340 (2129) ng/mL in the NRTI group and 5161 (2703) ng/mL in the NVP group (P = 0.140)., Conclusions: In antiretroviral-experienced subjects with sustained viral suppression, dual therapy with NVP plus LPV/rtv at standard dosage was as potent and safe as standard-of-care HAART at 48 weeks of follow-up. This approach may reduce mitochondrial toxicity and improve LPV/rtv-associated lipid abnormalities. The results of this pilot study support the study of this approach in a larger, randomized trial.

Background: It has been suggested that the addition of ribavirin (RBV) as a part of the treatment for chronic hepatitis C virus (HCV) in HIV co-infected patients on didanosine (ddI) or stavudine (d4T) might increase the nucleoside-induced impairment of mitochondrial function., Design: Comparative study to investigate the impact on mitochondrial function of adding RBV to a long-term treatment with ddI, d4T or both in HCV/HIV non-cirrhotic, asymptomatic patients. We included 26 patients: 16 continued with their current antiretroviral therapy (control group) and 10 patients received a concomitant 24-week course of RBV plus pegylated interferon (PEG-IFN) alpha-2b therapy (HCV-treated group)., Methods: We assessed peripheral blood mononuclear cells mitochondrial DNA (mtDNA) content and mitochondrial respiratory chain (MRC) function at baseline and at 24 weeks of follow-up. In the HCV-treated group we performed additional determinations at 12 weeks during anti-HCV therapy and 24 weeks after finishing anti-HCV therapy., Results: Times on ddI or d4T exposure were 194 +/- 54.9 and 131 +/- 66.5 weeks in the HCV-treated and control groups, respectively. There were no differences either in mtDNA content, the enzyme activity of MRC complexes or clinical parameters at baseline. Throughout the study, mitochondrial measurements remained stable within groups and without differences when we compared HCV-treated and control groups., Conclusions: In our study, the addition of RBV and PEG-IFN during a 24-week period in HCV/HIV non-cirrhotic, asymptomatic patients on long-term ddI, d4T or both had no impact on mitochondrial function. These findings could suggest that additional triggers are required to achieve a critical threshold in the degree of mitochondrial damage needed for symptoms to develop.

Introduction: Alternation of antiretroviral drug regimens has been proposed as a novel treatment strategy for HIV infection. However, some concerns persist regarding antiviral efficacy, adherence, toxicity and resistance evolution in the long term., Methods: A total of 161 antiretroviral-naive HIV-1-infected patients were randomized to receive stavudine/didanosine/efavirenz (group A) or zidovudine/lamivudine/ nelfinavir (group B) or to alternate between the two regimens every 3 months starting with regimen A (group C). Antiviral efficacy, adherence, safety and tolerability were analysed every 12 weeks., Results: After 96 weeks, time to virological failure was significantly delayed in the alternating regimen compared with the standards of care regimens. Virological suppression was seen in 46%, 48% and 58% of patients in groups A, B and C, respectively, in the intention-to-treat analysis and in 75%, 76% and 97% in the on-treatment analysis (A vs C: P=0.014; B vs C: P=0.016; A vs B: P=0.849). At the end of the study, 94% of patients in group A and 92% in groups B and C reported an adherence greater than 95%. Alternating therapy was associated with a similar impact on CD4+ counts in comparison with the standards of care regimens, as well as a lower mitochondrial DNA/nuclear DNA (mtDNA/nDNA) ratio decrease in the mitochondrial substudy performed on 37 patients. The frequency and intensity of adverse events in the alternating group decreased during subsequent cycles., Discussion: Our results favour the hypothesis that proactive therapy switching may delay the accumulation of resistance mutations. Moreover, the alternating regimen was well tolerated and adherence remained comparably high in all treatment groups. The lower mtDNA/nDNA ratio decrease observed in this group may imply a lower impact on mitochondrial toxicity than in standard regimens.

Objective: To validate users' perception of nurses' recommendations to look for another health resource among clients seeking teleadvice. To analyze the effects of different users' and call characteristics on the incorrectness of the self-report., Data Sources/study Setting: This study is a secondary analysis of data obtained from 4,696 randomly selected participants in a survey conducted in 1997 among users of Info-Santé CLSC, a no-charge telenursing health-line service (THLS) available all over the province of Québec., Study Design/data Collection: Self-reported advice from follow-up survey phone interviews, conducted within 48 to 120 hours after the participant's call were compared to the data consigned by the nurse in the computerized call record. Covariables concerned characteristics of callers, context of the calls, and satisfaction about the nurses' intervention. Association between these variables and inaccurate reports was identified using multinomial logistic regression analyses., Principal Findings: Advice to consult were recorded by the nurse in 42 percent of cases, whereas 39 percent of callers stated they had received one. Overall disagreement between the two sources is 27 percent (12 percent by false positive and 15 percent by false negative) and kappa is 0.45. Characteristics such as living alone (adjusted OR = 2.5), calls relating to psychological problems (OR = 2.8), perceived seriousness (OR = approximately 2.6), as well as others, were associated with inaccurate reports., Conclusions: Telephone health-line providers should be aware that many callers appear to interpret advice to seek additional health care differently than intended. Our findings suggest the need for continuing quality control interventions to reduce miscommunication, insure better understanding of advice by callers, and contribute to more effective service.

We examined the prevalence of cleavage site mutations, both within and outside the gag region, in 28 protease inhibitor (PI) cross-resistant patients treated with indinavir, ritonavir, and/or saquinavir compared to control patients treated with reverse transcriptase inhibitors. Three human immunodeficiency virus protease cleavage sites within gag (p2/NC, NC/p1, and NC/TFP) showed considerable in vivo evolution before and after therapy with indinavir, ritonavir, and/or saquinavir. Another gag cleavage site (p1/p6(gag)) showed a trend compared to matched controls. The other eight recognized cleavage sites showed relatively little difference between PI-resistant cases and controls. An A-->V substitution at the P2 position of the NC/p1 and NC/TFP cleavage sites was the most common (29%) change selected by the PIs used in this study.

Many recombinant proteins are synthesized as fusion proteins containing affinity tags to aid in the downstream processing. After purification, the affinity tag is often removed by using a site-specific protease such as factor Xa (FXa). However, the use of FXa is limited by its expense and availability from plasma. To develop a recombinant source of FXa, we have expressed two novel forms of FXa using baby hamster kidney (BHK) cells as host and the expression vector pNUT. The chimeric protein FIIFX consisted of the prepropeptide and the Gla domain of prothrombin linked to the activation peptide and protease region of FXa, together with a cellulose-binding domain (CBD(Cex)) as an affinity tag. A second variant consisted of the transferrin signal peptide linked to the second epidermal growth factor-like domain and the catalytic domain of FX and a polyhistidine tag. Both FX variants were secreted into the medium, their affinity tags were functional, and following activation, both retained FXa-specific proteolytic activity. However, the yield of the FIIFX-CBD(Cex) fusion protein was 10-fold higher than that of FX-CBD(Cex) and other forms of recombinant FX reported to date. The FXa derivatives were used to cleave two different fusion proteins, including a biologically inactive alpha-factor-hirudin fusion protein secreted by Saccharomyces cerevisiae. After cleavage, the released hirudin demonstrated biological activity in a thrombin inhibition assay, suggesting that this method may be applicable to the production of toxic or unstable proteins. The availability of novel FX derivatives linked to different affinity tags allows the development of a versatile system for processing fusion proteins in vitro., (Copyright 2000 Academic Press.)

Conservative Trp-to-Phe mutations were individually created in human thrombin at positions 60d, 96, 148, 207, and 215. Fluorescence intensities for these residues varied by a factor of 6. Residues 60d, 96, 148, and 215 transferred energy to the thrombin inhibitor 5-dimethylaminonaphthalene-1-sulfonylarginine-N-(3-ethyl-1,5- pentanediyl)amide efficiently, but residue 207 did not. Intensities correlated inversely with exposure to solvent, and measured and theoretical energy transfer efficiencies agreed well. Function was measured with respect to fibrinogen clotting, platelet and factor V activation, inhibition by antithrombin, and the thrombomodulin-dependent activation of protein C and thrombin-activable fibrinolysis inhibitor (TAFI). All activities of W96F and W207F ranged from 74 to 154% of the wild-type activity. This was also true for W148F, except for inhibition by antithrombin, where it showed 60% activity. W60dF was deficient by 30, 57, and 43% with fibrinogen clotting, platelet activation, and factor V cleavage (Arg(1006)), respectively. W215F was deficient by 90, 55, and 56% with fibrinogen clotting, platelet activation, and factor V cleavage (Arg(1536)). With protein C and TAFI, W96F, W148F, and W207F were normal. W60dF, however, was 76 and 23% of normal levels with protein C and TAFI, respectively. In contrast, W215F was 25 and 124% of normal levels in these reactions. Thus, many activities of thrombin are retained upon substitution of Trp with Phe at positions 96, 148, and 207. Trp(60d), however, appears to be very important for TAFI activation, and Trp(215) appears to very important for clotting and protein C activation.

Congenital dysfibrinogenemia is a rare cause of unexplained thrombosis. However, most individuals with dysfibrinogenemia are asymptomatic, suggesting that co-morbid factors contribute to thrombo-embolic events. The potential roles of additional genetic or acquired prothrombotic risk factors are poorly understood because detailed family studies are lacking. Herein, we describe a family whose propositus was a young Caucasian man with recurrent venous thrombo-emboli and dysfibrinogenemia due to heterozygosity for an Arg-->Cys substitution at residue 275 in the gamma-chain. The only additional thrombophilic abnormality found in the proband was heterozygosity for a G/A transition at position -455 in the fibrinogen beta-chain promoter; a genotype associated with high acute phase levels of fibrinogen. The proband's father, who died of a cerebral artery thrombosis, carried the gammaR275C substitution but not the beta-promoter -455 variant. Among 14 living relatives, eight were heterozygous for one or the other mutation and only one, a 21-year-old niece, was dually affected. None had suffered bleeding or thrombosis. In vitro studies of the proband's purified fibrinogen revealed markedly abnormal thrombin-catalyzed polymerization and delayed fibrin clot lysis by tPA-activated plasmin. We hypothesize that the gammaR275C substitution predisposes to thrombosis by generating clots that are relatively resistant to fibrinolysis. The clinical risk is low, however, in the absence of an additional thrombophilic mutation. The beta-promoter variant could, theoretically, contribute to this risk by augmenting expression of the dysfibrinogen under conditions of stress. Like the common hereditary thrombophilias, heterozygous familial dysfibrinogenemia induces thrombosis in the setting of multiple prothrombotic influences., (Copyright 2000 Wiley-Liss, Inc.)

Human immunodeficiency virus (HIV) type 1 drug-resistance testing is quickly moving from the research laboratory to the clinic as data defining its utility as a prognostic indicator of response to therapy become available. In July 1998, a panel of the International AIDS Society-USA did not recommend the widespread application of resistance testing, but by May 2000 this panel endorsed and recommended the incorporation of resistance testing in patient-care management. Considerable data supporting the use of drug-resistance testing have now been published or presented at international conferences. These data strongly suggest that drug-resistance testing is of considerable value in many clinical settings. Prospective trials of resistance testing as a clinical management tool are still ongoing, and the long-term benefits still need to be evaluated. Nevertheless, early results from several studies showed a significantly better virological response when treatment regimens were based on resistance-testing data, rather than on the standard of care. HIV drug-resistance testing is also useful as a tool for new antiretroviral drug design and development, as well as for monitoring the spread of primary HIV drug resistance.

We attempted to characterize circadian variations in pharmacokinetic parameters of a new formulation of cyclosporine (CsA) in nine cardiac allograft recipients. A secondary objective was to determine the sampling time that correlated best with exposure of patients to the drug. This was a two-period study with each period lasting 12 hours. All patients received two equal doses of a new microemulsion of CsA 12 hours apart. Blood samples to measure drug levels were obtained at administration and 1, 2, 3, 4, 6, 9, and 12 hours after each dose. We found no statistically significant difference in pharmacokinetic parameters (areas under the curve, minimum blood concentration, oral clearance) measured during the day and during the night. However, maximum blood concentrations during the day were 30% higher than those at night (p<0.05). We found a good correlation between minimum concentrations in the morning and overall exposure of patients to CsA (r=0.89). This new microemulsion appears to have few circadian variations of blood concentrations in cardiac transplant recipients. The clinical significance of higher maximum blood concentration during daytime remains to be elucidated. Our results support the most widely accepted method for monitoring CsA, which is based on minimum concentrations in the morning.

Meizothrombin and meizothrombin(desF1) are intermediates formed during the conversion of prothrombin to thrombin by factor Xa, factor Va, phospholipids, and Ca2+ (prothrombinase). These intermediates are active toward synthetic peptide substrates but have limited ability to interact with platelets or macromolecular substrates such as fibrinogen. Meizothrombin and meizothrombin(desF1) activate protein C, however, and may exert primarily an anticoagulant effect. In this study, we investigated the inhibition of meizothrombin and meizothrombin(desF1) by two glycosaminoglycan-dependent protease inhibitors, heparin cofactor II (HCII) and antithrombin (AT). Purified recombinant meizothrombin and meizothrombin(desF1) were inhibited by HCII in the presence of dermatan sulfate with maximal second-order rate constants of 8 x 10(6) M-1.min-1 and 1.8 x 10(7) M-1.min-1, respectively, but were inhibited less than one-tenth as fast by AT in the presence of heparin. Similarly, the products of the prothrombinase reaction were inhibited in situ more effectively by HCII than by AT. When HCII and dermatan sulfate were present continuously during the prothrombinase reaction, meizothrombin was trapped as a sodium dodecyl sulfate-stable complex with HCII and no amidolytic activity could be detected with a thrombin substrate. Our findings indicate that HCII is an effective inhibitor of meizothrombin and meizothrombin(desF1) and, therefore, might regulate the anticoagulant activity of these proteases.

After vascular injury, a cascade of serine protease activations leads to the conversion of the soluble fibrinogen molecule into fibrin. The fibrin monomers then polymerize spontaneously and noncovalently to form a fibrin gel. The primary interaction of this polymerization reaction is between the newly exposed N-terminal Gly-Pro-Arg sequence of the alpha chain of one fibrin molecule and the C-terminal region of a gamma chain of an adjacent fibrin(ogen) molecule. In this report, the polymerization pocket has been identified by determining the crystal structure of a 30-kDa C-terminal fragment of the fibrin(ogen) gamma chain complexed with the peptide Gly-Pro-Arg-Pro. This peptide mimics the N terminus of the alpha chain of fibrin. The conformational change in the protein upon binding the peptide is subtle, with electrostatic interactions primarily mediating the association. This is consistent with biophysical experiments carried out over the last 50 years on this fundamental polymerization reaction.

A patient had both lupus anticoagulant hypoprothrombinemia syndrome and celiac disease. The presence of a neutralizing antiprothrombin antibody in the patient's serum was demonstrated by coagulation tests, immunoadsorption, and Western blot analysis. The probable cause for the severe hypoprothrombinemia was clearance of prothrombin-antibody complexes from the circulation. Studies showed the antiprothrombin antibody binding to human prothrombin was phospholipid- and Ca(++)-independent; the antibody did not bind to human thrombin. The target epitope of the antibody was studied by Western blot analysis of mutated recombinant human prothrombin molecules. The antibody reacted with the fragment 2-A region of prothrombin, spanning the second kringle domain and the thrombin A chain within prothrombin. Based on this new method, the proposed mechanism for the neutralizing action of the antibody is impairment of prothrombin activation by the prothrombinase complex, either by steric hindrance of the hydrolysis of prothrombin by factor Xa or by interference of the interaction of prothrombin with factor Va; both reactions are required for efficient conversion of prothrombin to thrombin.