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Biomedical subjects

James Smith

Publications and source records attributed to James Smith.

At least 19 recordsLinked to original sources
PubMed2026

Cardiorespiratory training for people with stroke.

RATIONALE: Low levels of cardiorespiratory fitness are common after stroke and are associated with post-stroke disability and increased risk of secondary stroke. Cardiorespiratory training interventions aim to increase cardiorespiratory fitness, improve physical function, reduce disability, and help prevent future strokes. Clinical guidelines recommend exercise as part of lifestyle modification for secondary prevention, and strongly recommend exercise for rehabilitation. This review is one of three reviews that were originally a single review on physical fitness training for stroke. OBJECTIVES: The primary objective of this review was to determine whether cardiorespiratory training after stroke has an effect on death, disability, adverse events, risk factors, fitness, walking, and indices of physical function when compared to a non-exercise control. SEARCH METHODS: In April 2025, we searched nine bibliographic databases and two trials registers to identify studies for inclusion in the review. We checked reference lists, tracked citations, and contacted experts. ELIGIBILITY CRITERIA: We included randomised controlled trials comparing cardiorespiratory training interventions with usual care, no intervention, or a non-exercise intervention in people with stroke. OUTCOMES: Our critical outcomes were death, disability, adverse events, risk factors, fitness, walking, and indices of physical function, assessed at the end of the intervention and the end of the longest follow-up. RISK OF BIAS: We used the Cochrane RoB 1 tool to assess the risk of bias in the included studies. SYNTHESIS METHODS: The studies evaluated different comparisons (e.g. cardiorespiratory training versus no intervention/waiting list control or versus attention control or versus usual care), which we synthesised into a single comparison: cardiorespiratory training versus control. We used random-effects meta-analysis on arm-level data (risk difference (RD) for dichotomous data, and mean difference (MD) or standardised mean difference (SMD) for continuous data, with 95% confidence intervals (CIs)). For outcome data that we did not meta-analyse, we followed Synthesis Without Meta-analysis (SWiM) guidance. We used GRADE to assess the certainty of the evidence for critical outcomes. INCLUDED STUDIES: We included 53 studies (2672 participants, with an average age of 61.9 years). Most studies recruited ambulatory participants in the early subacute (7 days to 3 months) or chronic (> 6 months) phases of recovery. Exercise duration recommendations were met in 49 studies, and frequency recommendations in 48. Twenty-eight studies lacked balanced exposure between groups. Programme duration was 12 weeks or more in 16 studies (maximum: 24 weeks). Sixteen studies had a post-intervention follow-up period (12 weeks to 12 months from baseline). One study planned a six-month follow-up but did not report it. SYNTHESIS OF RESULTS: Cardiorespiratory training does not increase or decrease deaths at the end of intervention (RD 0.00, 95% CI -0.01 to 0.01; 36 studies, 1563 participants; high-certainty evidence) or the end of follow-up (RD -0.00, 95% CI -0.02 to 0.02; 10 studies, 713 participants; high-certainty evidence). Cardiorespiratory training may improve indices of disability slightly at the end of intervention (SMD 0.35, 95% CI 0.12 to 0.57; 17 studies, 1073 participants; very low-certainty evidence), but the evidence is very uncertain. Re-expressed using the Barthel Index (0 to 20), the equivalent effect is MD 1.68, 95% CI 0.59 to 2.74. It is unclear if the effect is clinically meaningful (the minimal clinically important difference (MCID) is +1.85). The effect is unclear at the end of follow-up (SMD -0.14, 95% CI -0.36 to 0.08; 5 studies, 347 participants; low-certainty evidence). Cardiorespiratory training does not increase or decrease the incidence of secondary cardiovascular or cerebrovascular events at the end of intervention (RD -0.00, 95% CI -0.03 to 0.02; 8 studies, 544 participants; high-certainty evidence) and probably does not affect them at the end of follow-up (RD -0.02, 95% CI -0.08 to 0.04; 4 studies, 412 participants; moderate-certainty evidence). It is very uncertain whether cardiorespiratory training affects systolic blood pressure (mmHg) at the end of intervention (MD -2.12, 95% CI -5.81 to 1.57; 9 studies, 535 participants; very low-certainty evidence) (MCID -2 mmHg) or follow-up (MD 0.93, 95% CI -4.30 to 6.16; 3 studies, 155 participants; very low-certainty evidence); the 95% CIs include the MCID. Cardiorespiratory training probably results in a slight improvement in cardiorespiratory fitness (VO2 ml/kg/min) at the end of intervention (MD 2.37, 95% CI 1.39 to 3.36; 13 studies, 608 participants; moderate-certainty evidence); it is unclear if the effect is clinically meaningful (MCID +3.5 ml/kg/min). The effect may be similar at the end of follow-up (MD 2.76, 95% CI 1.36 to 4.16; 5 studies, 237 participants; low-certainty evidence). Subgroup analysis favoured longer interventions. Cardiorespiratory training probably results in a slight increase in comfortable walking speed (metres per second) at the end of intervention (MD 0.08, 95% CI 0.04 to 0.12; 16 studies, 647 participants; moderate-certainty evidence), but the effect is not clinically meaningful (MCID +0.13). The effect is unclear at the end of follow-up (MD 0.02, 95% CI -0.05 to 0.10; 3 studies, 182 participants; low-certainty evidence). Cardiorespiratory training may improve indices of balance at the end of intervention (SMD 0.31, 95% CI 0.15 to 0.47; 18 studies, 772 participants; very low-certainty evidence), but the evidence is very uncertain. Re-expressing using the Berg Balance Scale, the equivalent effect is MD 2.09, 95% CI 1.10 to 3.07; and it is unclear if it is clinically meaningful (MCID of +2). The effect is unclear at the end of follow-up (MD 0.90, 95% CI -1.32 to 3.12; 6 studies, 253 participants; low-certainty evidence). Overall, our certainty about the evidence is limited for most outcomes by imprecision (small number of studies and participants) or risks of bias (e.g. imbalanced exposure doses) or both. AUTHORS' CONCLUSIONS: Cardiorespiratory training after stroke does not affect mortality or the incidence of secondary events at the end of the aerobic exercise training programme or end of follow-up. It may increase fitness, reduce disability, increase walking speed, and improve balance at the end of intervention, but it is unclear if these improvements are clinically meaningful. Further well-designed randomised trials are needed to fully understand the potential benefits and long-term effects of cardiorespiratory training and the optimal exercise prescription. FUNDING: No dedicated funding REGISTRATION: Protocol (and previous versions) available via DOI 10.1002/14651858.CD003316.

Humans↗
PubMed2025

Tau uptake by human neurons depends on receptor LRP1 and kinase LRRK2.

Extracellular release and uptake of pathogenic forms of the microtubule-associated protein tau contribute to the pathogenesis of several neurodegenerative diseases, including Alzheimer's disease. Defining the cellular mechanisms and pathways for tau entry to human neurons is essential to understanding tauopathy pathogenesis and enabling the rational design of disease-modifying therapeutics. Here, whole-genome, loss-of-function CRISPR screens in human iPSC-derived excitatory neurons, the major neuronal cell type affected in these diseases, provide insights into the different cellular pathways for uptake of extracellular monomeric and fibrillar tau. Monomeric and fibrillar tau are both taken up by human neurons by receptor-mediated endocytosis, but involve different routes of entry at the neuronal surface: the low-density lipoprotein LRP1 is the primary receptor for monomeric tau, but contributes less to fibrillar tau entry. Similarly, endocytosis of monomeric tau is dependent on the familial Parkinson's disease gene LRRK2, but not required for endocytosis of fibrillar tau. These findings implicate LRP1 and LRRK2 in the pathogenesis of tauopathies and Parkinson's disease, and identify LRRK2 as a potential therapeutic target for altering progression of these diseases.

Humans↗
PubMed2006

Long-term variations in human T lymphotropic virus (HTLV)-I and HTLV-II proviral loads and association with clinical data.

BACKGROUND: The human T lymphotropic virus (HTLV)-I or -II proviral load (VL) may be linked to viral pathogenesis, but prospective data on VL and disease outcomes are lacking. METHODS: Using data from a prospective cohort study of HTLV disease outcomes, we examined baseline VLs with real-time quantitative polymerase chain reaction in 122 HTLV-I- and 319 HTLV-II-infected subjects and serial VLs over the course of 6 visits in a subset of 30 HTLV-I- and 30 HTLV-II-infected subjects. Cox and logistic-regression models were used to test baseline associations, and repeated-measures analysis was used to study variations in VL over time. RESULTS: Over the course of a median of 10.4 years, HTLV-I VLs decreased slightly (slope, -0.017 log(10) copies/10(6) peripheral blood mononuclear cells [PBMCs]/year; P=.042) and HTLV-II VLs did not change (slope, -0.019 log(10) copies/10(6) PBMCs/year; P=.165). Changes in VL over time were associated positively with alcohol use (P=.07) and negatively with black race (P=.03) for HTLV-I and positively with smoking (P=.08) for HTLV-II. In the larger group, there was no association between baseline VL and disease outcomes. In the smaller group with serial VL data, there was an association between increasing VL and bladder or kidney infections for both HTLV-I (P=.005) and HTLV-II (P=.022). CONCLUSIONS: HTLV VLs are stable over time, but alcohol and tobacco intake may affect the progression of VLs. The association between increasing VLs and bladder/kidney infection may be explained by early HTLV-related neuropathologic progression.

Adult↗
PubMed2006

A role for Dicer in immune regulation.

Micro RNAs (miRNAs) regulate gene expression at the posttranscriptional level. Here we show that regulatory T (T reg) cells have a miRNA profile distinct from conventional CD4 T cells. A partial T reg cell-like miRNA profile is conferred by the enforced expression of Foxp3 and, surprisingly, by the activation of conventional CD4 T cells. Depleting miRNAs by eliminating Dicer, the RNAse III enzyme that generates functional miRNAs, reduces T reg cell numbers and results in immune pathology. Dicer facilitates, in a cell-autonomous fashion, the development of T reg cells in the thymus and the efficient induction of Foxp3 by transforming growth factor beta. These results suggest that T reg cell development involves Dicer-generated RNAs.

Animals↗
PubMed2006

Pharmacokinetics of oseltamivir in young and very elderly subjects.

BACKGROUND: Pharmacokinetic studies of oseltamivir in very elderly patients (> or = 80 y) have not previously been performed. OBJECTIVE: To compare the pharmacokinetics of oseltamivir and the active carboxylate metabolite in healthy young and very elderly Japanese subjects. METHODS: Young (20-35 y, fasting, n = 7) and very elderly subjects (> or = 80 y, fed, n = 5) were enrolled in single-center studies and received a single oral dose of oseltamivir 75 mg. Plasma and urine samples were collected (24 h) for pharmacokinetic analysis, and safety was assessed. RESULTS: The time to maximum plasma concentration (tmax) for oseltamivir was delayed in the very elderly compared with the young subjects (2.30 vs 0.71 h, respectively). Furthermore, oseltamivir maximum plasma concentration (Cmax) and AUC(inf) were 52% and 80% higher, respectively, in the very elderly compared with the young subjects. Oral clearance was 45% lower in elderly patients, possibly due to the effects of administration of oseltamivir with a meal. For the active metabolite, oseltamivir carboxylate, Cmax and AUC(inf) values were, respectively, 22% and 91% higher in the very elderly subjects than in the young subjects, while oral clearance was 50% lower in the elderly population. The increased exposure of the active metabolite is likely to correlate with an age-related decline in renal function. For both oseltamivir and the active metabolite, there was large interpatient variability in the Cmax values. The data reported here indicate that oseltamivir would be effective in both of these populations, as trough concentrations for the active metabolite at 12 and 24 hours exceeded the 50% inhibitory concentration against the neuraminidase of influenza A and B isolates by more than 50-fold. Oseltamivir was well tolerated in both groups. CONCLUSIONS: Exposures (AUC(inf)) to both the parent drug and active metabolite were increased by more than 80% in the small number of very elderly subjects presented here. However, oseltamivir was well tolerated by these subjects.

Adult↗
PubMed2006

CapZ-lipid membrane interactions: a computer analysis.

BACKGROUND: CapZ is a calcium-insensitive and lipid-dependent actin filament capping protein, the main function of which is to regulate the assembly of the actin cytoskeleton. CapZ is associated with membranes in cells and it is generally assumed that this interaction is mediated by polyphosphoinositides (PPI) particularly PIP2, which has been characterized in vitro. RESULTS: We propose that non-PPI lipids also bind CapZ. Data from computer-aided sequence and structure analyses further suggest that CapZ could become partially buried in the lipid bilayer probably under mildly acidic conditions, in a manner that is not only dependent on the presence of PPIs. We show that lipid binding could involve a number of sites that are spread throughout the CapZ molecule i.e., alpha- and beta-subunits. However, a beta-subunit segment between residues 134-151 is most likely to be involved in interacting with and inserting into lipid membrane due to a slighly higher ratio of positively to negatively charged residues and also due to the presence of a small hydrophobic helix. CONCLUSION: CapZ may therefore play an essential role in providing a stable membrane anchor for actin filaments.

Actins↗
PubMed2006

Effects of the dual 5 alpha-reductase inhibitor dutasteride on apoptosis in primary cultures of prostate cancer epithelial cells and cell lines.

BACKGROUND: The profound reduction in serum dihydrotestosterone (DHT) observed with the dual 5 alpha-reductase inhibitor (5ARI) dutasteride makes it an attractive agent for prostate cancer therapy. The objective of the current study was to determine whether dutasteride would induce apoptosis in a range of prostate epithelial cell lines and primary cultures. METHODS: Both human prostate androgen-sensitive cell lines (PwR-1E, PNT-2, LNCaP, and PC3[AR2]) and an androgen-independent cell line (PC-3) were grown to confluence. Primary epithelial cells extracted from fresh prostate cancer radical prostatectomy specimens also were grown to confluence under optimal conditions. Total cellular protein was extracted to confirm cytokeratin 18 and antihuman alpha-methylacyl-CoA racemase (AMACR) expression of the primary cells. Apoptosis was assessed by propidium iodide DNA staining and flow cytometry after 24 hours of culture in from 0 microM to 10 microM of dutasteride. RESULTS: Dutasteride induced a dose-dependent increase in apoptosis in the androgen-sensitive prostate cell lines PwR-1E, PNT-2, and LNCaP and in the androgen receptor-expressing PC3(AR2) cell line. However, there was no significant apoptosis noted in the parental PC-3 cells. Of 16 primary epithelial cultures that were treated, 7 cultures were induced to undergo apoptosis, and 9 cultures were unresponsive. All primary cultures were positive for cytokeratin 18 expression, confirming their epithelial phenotype. Responder epithelial cells were positive for AMACR expression. CONCLUSIONS: The results of the current study confirmed that dutasteride differentially induced apoptosis in a subset of prostate cell lines and primary prostate epithelial cells. Understanding the cellular phenotype may indicate susceptible cells.

Apoptosis↗
PubMed2006

Effect of benefits counseling services on employment outcomes for people with psychiatric disabilities.

OBJECTIVE: This study examined the impact of specialized benefits counseling services on levels of competitive employment for people with psychiatric disabilities receiving Social Security Administration (SSA) disability benefits in Vermont. METHODS: Beneficiaries who had a psychiatric disability and who received specialized benefits counseling (N = 364) were compared with matched contemporaneous and historical control participants over four years, two years before and two years after the initiation of the intervention. Study participants were consumers of vocational rehabilitation services, and the outcome measure was quarterly earnings from state unemployment insurance program records. Benefits counseling included general education regarding SSA disability programs, the various work incentives available under those programs, and other federal and state public benefits; individualized research and counseling regarding enrollees' current benefits packages; assistance in managing benefits through the transition to employment; and provision of information to supporting professionals. RESULTS: Participants who received specialized benefits counseling achieved significantly greater improvements in earnings. The benefits counseling group increased its adjusted average earnings by 1,256 dollars per year in comparison with the two control groups. CONCLUSIONS: Specialized benefits counseling appears to be an important employment support for Social Security Administration disability beneficiaries who have psychiatric disabilities.

Adolescent↗
PubMed2006

Circular fingerprints: flexible molecular descriptors with applications from physical chemistry to ADME.

Circular fingerprints -- the representation of molecular structures by atom neighborhoods -- have been applied to a wide range of applications, such as similarity searching and the prediction of absorption, distribution, metabolism, excretion and toxicity properties. In recent years there has been a surge in applications resulting from the superior performance of circular fingerprints in comparative studies. This feature examines the nature of circular fingerprints as well as their applications, including virtual screening, metabolism prediction and the estimation of pK((a)) constants.

Algorithms↗
PubMed2005

Comparative immunogenicity in rhesus monkeys of multi-protein HIV-1 (CRF02_AG) DNA/MVA vaccines expressing mature and immature VLPs.

We developed an AIDS vaccine for Western and West-Central Africa founded on HIV-1 subtype CRF02_AG. Rhesus macaques were primed with Gag-Pol-Env-expressing plasmid DNA and boosted with a recombinant modified vaccinia virus Ankara (rMVA), expressing matched proteins. Two DNA vaccine constructs (IC1-90 and IC48) that differed by point mutations in gag and pol were compared. IC1-90 produces primarily immature (core comprises unprocessed Pr55Gag) HIV-like particles (VLPs) and IC48 produces mature VLP with processed Pr55Gag, immature VLP, and intracellular protein aggregates. Both vaccines raised significant cellular responses for Gag, Pol, and Env. Approximate twofold higher ELISPOT responses to Gag and Env epitopes were observed for IC48 animals than for IC1-90 animals at the peak post-MVA effector (P = 0.028) and late memory (P = 0.051) phases, respectively. Greater breadth for IC48-primed animals was observed than for IC1-90-primed animals at peak response (P = 0.03). Our results indicated that the vaccines elicited high frequency T cell responses and primed anti-Env antibody. They also suggest that expression of different forms of VLP has a significant effect on elicited cellular and humoral immunity.

AIDS Vaccines↗
PubMed2005

Genomic characterisation of a Fgf-regulated gradient-based neocortical protomap.

Recent findings support a model for neocortical area formation in which neocortical progenitor cells become patterned by extracellular signals to generate a protomap of progenitor cell areas that in turn generate area-specific neurons. The protomap is thought to be underpinned by spatial differences in progenitor cell identity that are reflected at the transcriptional level. We systematically investigated the nature and composition of the protomap by genomic analyses of spatial and temporal neocortical progenitor cell gene expression. We did not find gene expression evidence for progenitor cell organisation into domains or compartments, instead finding rostrocaudal gradients of gene expression across the entire neocortex. Given the role of Fgf signalling in rostrocaudal neocortical patterning, we carried out an in vivo global analysis of cortical gene expression in Fgfr1 mutant mice, identifying consistent alterations in the expression of candidate protomap elements. One such gene, Mest, was predicted by those studies to be a direct target of Fgf8 signalling and to be involved in setting up, rather than implementing, the progenitor cell protomap. In support of this, we confirmed Mest as a direct transcriptional target of Fgf8-regulated signalling in vitro. Functional studies demonstrated that this gene has a role in establishing patterned gene expression in the developing neocortex, potentially by acting as a negative regulator of the Fgf8-controlled patterning system.

Animals↗
PubMed2005

Complex haplotypes, copy number polymorphisms and coding variation in two recently divergent mouse strains.

Inbred mouse strains provide the foundation for mouse genetics. By selecting for phenotypic features of interest, inbreeding drives genomic evolution and eliminates individual variation, while fixing certain sets of alleles that are responsible for the trait characteristics of the strain. Mouse strains 129Sv (129S5) and C57BL/6J, two of the most widely used inbred lines, diverged from common ancestors within the last century, yet very little is known about the genomic differences between them. By comparative genomic hybridization and sequence analysis of 129S5 short insert libraries, we identified substantial structural variation, a complex fine-scale haplotype pattern with a continuous distribution of diversity blocks, and extensive nucleotide variation, including nonsynonymous coding SNPs and stop codons. Collectively, these genomic changes denote the level and direction of allele fixation that has occurred during inbreeding and provide a basis for defining what makes these mouse strains unique.

Animals↗
PubMed2005

A prospective study of sexual transmission of human T lymphotropic virus (HTLV)-I and HTLV-II.

BACKGROUND: Cross-sectional studies support sexual transmission of human T lymphotropic virus (HTLV)-I/II; however, prospective incidence data, particularly for HTLV-II, are limited. METHODS: A cohort of 85 HTLV-positive (30 with HTLV-I and 55 with HTLV-II) blood donors and their stable (>or=6 months) heterosexual sex partners were followed biannually over the course of a 10-year period. RESULTS: Four of 85 initially seronegative sex partners of HTLV-I and -II carriers seroconverted, for an incidence rate (IR) of 0.6 transmissions/100 person-years (py) (95% confidence interval [CI], 0.2-1.6). This includes 2 HTLV-I transmissions/219 py (IR, 0.9 transmissions/100 py [95% CI, 0.1-3.3]) and 2 HTLV-II transmissions/411 py (IR, 0.5 transmissions/100 py [95% CI, 0.06-1.8]), with no significant difference by HTLV type. There were 2 male-to-female (IR, 1.2 transmissions/100 py [95% CI, 0.1-4.3]) and 2 female-to-male (IR, 0.4 transmissions/100 py [95% CI, 0.05-1.6) transmissions. HTLV-I or -II proviral load was 2 log10 lower in newly infected partners than in index positive partners who transmitted HTLV (P=.007). CONCLUSIONS: The incidence of sexual transmission of HTLV-II may be similar to that of HTLV-I, and female-to-male transmission may play a more important role than previously thought. HTLV-I and -II proviral load may be lower in sexually acquired infection, because of a small infectious dose.

Adult↗
PubMed2005

Axenfeld-Rieger malformation and distinctive facial features: Clues to a recognizable 6p25 microdeletion syndrome.

Deletion of distal 6p is associated with a distinctive clinical phenotype including Axenfeld-Rieger malformation, hearing loss, congenital heart disease, dental anomalies, developmental delay, and a characteristic facial appearance. We report the case of a child where recognition of the specific ocular and facial phenotype, led to identification of a 6p microdeletion arising from a de novo 6:18 translocation. Detailed analysis confirmed deletion of the FOXC1 forkhead gene cluster at 6p25. CNS anomalies included hydrocephalus and hypoplasia of the cerebellum, brainstem, and corpus callosum with mild to moderate developmental delay. Unlike previous reports, hearing was normal.

Abnormalities, Multiple↗
PubMed2005

Oseltamivir (Tamiflu) and its potential for use in the event of an influenza pandemic.

Recent cross species transmission of avian influenza has highlighted the threat of pandemic influenza. Oseltamivir (Tamiflu) has been shown to be effective in the treatment and prevention of epidemic influenza infection in adults, adolescents and children (> or = 1 year). Although oseltamivir has not been approved for prophylactic use in children, it has been shown to be effective. Oseltamivir is also active against avian influenza virus strains. Evidence suggests that lower doses or shorter durations of treatment/chemoprophylaxis other than those approved may not be effective and may contribute to emergence of viral resistance. Safety data from dose ranging studies show that 5 day courses of 150 mg twice daily for treatment and 6 week courses of 75 mg twice daily for prophylaxis were as well tolerated as the approved dose regimens. The use of oseltamivir in a pandemic is influenced by the goals of the pandemic plan developed by the responsible Government and Health Authority. To optimize use of antiviral medications, processes will be needed to collect, collate and report outcome data from treated patients and/or from use for chemoprophylaxis of pandemic influenza during the first-wave outbreaks. If oseltamivir is included in a national or regional pandemic plan, stockpiling of the material, either in the form of capsules or the bulk active pharmaceutical ingredient will be necessary. In the absence of a stockpile, there is no guarantee that an adequate supply of oseltamivir will be available.

Acetamides↗