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OBJECTIVE: The aim of this paper is to explore the longitudinal relationships between physical and psychological symptoms and immunological factors following acute infective illnesses. METHOD: Preliminary data from a prospective investigation of patients with serologically proven acute infectious illnesses due to Epstein-Barr virus (EBV), Ross River virus (RRV) or Q fever are reported. Patients were assessed within 4 weeks of onset of symptoms and then reviewed 2 and 4 weeks later. Physical illness data were collected at interview. Psychological and somatic symptom profiles were assessed by standardised self-report questionnaires. Cell-mediated immune (CMI) function was assessed by measurement of delayed-type hypersensitivity (DTH) skin responses. RESULTS: Thirty patients who had been assessed and followed over the 4-week period (including 17 patients with EBV, five with RRV and eight with Q fever) were included in this analysis. During the acute phase, profound fatigue and malaise were the most common symptoms. Classical depressive and anxiety symptoms were not prominent. Initially, 46% of cases had no DTH skin response (i.e. cutaneous anergy) indicative of impaired cellular immunity. Over the 4-week period, there was a marked improvement in both somatic and psychological symptoms, although fatigue remained a prominent feature in 63% of subjects. The reduction in reported fatigue was correlated with improvement in the DTH skin response (p = 0.001) and with improvement in General Health Questionnaire (GHQ) scores (p < 0.01). CONCLUSIONS: Acute infectious illnesses are accompanied by a range of nonspecific somatic and psychological symptoms, particularly fatigue and malaise rather than anxiety and depression. Although improvement in several symptoms occurs rapidly, fatigue commonly remains a prominent complaint at 4 weeks. Resolution of fatigue is associated with improvement in cell-mediated immunity. [ABSTRACT FROM AUTHOR]

The Ni/PPh 3 -catalyzed homocoupling of aryl chlorides in DMF using Zn as the stochiometric reducing agent is one of a general class of Ni-catalyzed processes, where the mechanism has been a matter of long-standing debate. This study re-evaluates prior conclusions and insights. NMR spectroscopy is used to identify [(PPh 3 ) 2 Ni II (Ar)Cl] as a key intermediate and to explore the indirect roles of using Zn as the reductant. The [ZnCl 2 ] coproduct is responsible for several features, including a sequential transmetalation pathway involving [ArZnCl]. [ZnCl 2 ] also abstracts halide from [(PPh 3 ) 2 NiCl 2 ] to generate [Ni II Cl(DMF) 5 ] + [ZnCl 3 (DMF)] - , and in doing so, affects the Ni II + Ni 0 ↔ 2 Ni I speciation. [ZnCl 2 ] thus acts as an accelerator and inhibitor, resulting in mildly sigmoidal reaction profiles. When the [ZnCl 2 ] concentration becomes too high or the phosphine ligand concentration too low, catalysis stalls. Turnover is restored by the addition of further phosphine ligand, or chloride ion. In the presence of an exogenous chloride ion, turnover is rapid, again proceeding via [(PPh 3 ) 2 Ni II (Ar)Cl] but via dinuclear metathesis. The generation of [ZnCl 3 (DMF)] - results in mutually antagonistic effects between [ZnCl 2 ] and [Cl] - such that turnover proceeds via one mechanism or the other, depending on which species is in excess. The intermediacy of [ArZnCl] suggests a solution to the long-standing anomaly that many other reductants were found to be much less effective than Zn in inducing turnover of Ni/PPh 3 catalyzed aryl chloride homocoupling in DMF. The use of DMAc as a solvent in place of DMF inhibits stalling through the steric inhibition of mixed metalate generation.

Aims: This study aims to determine whether intraoperative intravenous (IV) tranexamic acid (TXA) affects blood loss following the surgical management of femoral fragility fractures (FFF)., Methods: This was a single centre (university teaching hospital) non-randomised case-control study. There were 361 consecutive patients with FFF admitted over a 4-month period were included (mean age 81.4yrs; mean BMI 23.5; 73.7% female). Patient demographics, comorbidities, preoperative anticoagulation use, surgical management, intravenous TXA use, perioperative haemoglobin (Hb) and haematocrit, and requirement for blood transfusion were recorded. The primary outcome was postoperative blood transfusion requirement. Secondary outcomes included postoperative day one calculated blood loss (CBL) (using the Nadler and Gross formulae) and fall in Hb (percentage) from preoperative levels; and the incidence of thrombotic events and mortality up to 30 days., Results: Groups were well matched in terms of patient demographics, comorbidities, preoperative anticoagulation use, injury types and surgical management. Intravenous TXA 1 g given at the beginning of surgery at the discretion of the operating team: 178 (49%) received TXA and 183 (51%) did not. The requirement for postoperative blood transfusion was significantly less in the TXA group: 15/178 (8.4%) compared to 58/183 (31.7%) (p < 0.001; Chi square). TXA significantly reduced both the percentage fall in Hb (mean difference 4.3%, p < 0.001) and the CBL (mean difference -222 ml, p < 0.001). There was no difference in VTE (2 vs 1, p = 0.620) or other thrombotic events (2 vs 0, p = 0.244) between groups., Conclusion: 1 g of intraoperative intravenous TXA during the surgical management of FFF was associated with reduced rate of transfusion, CBL and the percentage drop in HB. The use of TXA in this study was not randomised, so there could be un-quantifiable bias in the patient selection., (© 2023. The Author(s).)

Facioscapulohumeral muscular dystrophy (FSHD) is caused by misexpression of the DUX4 transcription factor in skeletal muscle that results in transcriptional alterations, abnormal phenotypes and cell death. To gain insight into the kinetics of DUX4-induced stresses, we activated DUX4 expression in myoblasts and performed longitudinal RNA sequencing paired with proteomics and phosphoproteomics. This analysis revealed changes in cellular physiology upon DUX4 activation, including DNA damage and altered mRNA splicing. Phosphoproteomic analysis uncovered rapid widespread changes in protein phosphorylation following DUX4 induction, indicating that alterations in kinase signaling might play a role in DUX4-mediated stress and cell death. Indeed, we demonstrate that two stress-responsive MAP kinase pathways, JNK and p38, are activated in response to DUX4 expression. Inhibition of each of these pathways ameliorated DUX4-mediated cell death in myoblasts. These findings uncover that the JNK pathway is involved in DUX4-mediated cell death and provide additional insights into the role of the p38 pathway, a clinical target for the treatment of FSHD., Competing Interests: Competing interests At the time that these studies were performed, C.M.B., A.S.H., M.S.A., X.L., V.M., S.G., L.X., T.G., A.H., M.M., R.M., J.O., and N.C. were all Pfizer employees and declare potential conflicts of interest due to income received from their employment., (© 2022. Published by The Company of Biologists Ltd.)

Aims: This study investigated the perceptions of medical students regarding the barriers to pursuing a career in trauma and orthopaedics (T&O); and whether these perceptions were altered by attending an event promoting women in T&O., Methods: An event consisting of presentations and interactive sessions from two female T&O trainees was hosted online. Attendees completed pre and post-event questionnaires. Students were asked about their previous exposure to T&O, perceptions of gender imbalances in T&O and what barriers they perceived prevented women from entering T&O. Univariate analysis was performed to identify changes in perceptions following the event., Results: Pre-event questionnaires were completed by 102 people; and post-event by 52. Although 64/102 respondents were considering a career in T&O, 26/102 were dissuaded by perceived gender disparities. Perceptions of gender disparities were significantly higher in UK based attendees compared to other nationalities ( p  = 0.047). Attendees were more likely to want to pursue a career in T&O if they had been directly exposed at medical school ( p  = 0.044), but exposure did not alter perceptions of women in T&O. The most common perceived barrier was the orthopaedic stereotype followed by male dominated workplace culture, and lack of female role models. Pre and post-event responses did not differ significantly for any areas examined., Conclusion: There are significant concerns amongst medical students regarding gender based discrimination within T&O, and these perceptions were not altered by attending a one-off women in T&O event. Early exposure to T&O appears important to improve interest in orthopaedics, whereas negative stereotyping is a barrier., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hull, Pestrin, Brennan, Hackney and Scott.)

Objective: We assessed whether famotidine improved inflammation and symptomatic recovery in outpatients with mild to moderate COVID-19., Design: Randomised, double-blind, placebo-controlled, fully remote, phase 2 clinical trial (NCT04724720) enrolling symptomatic unvaccinated adult outpatients with confirmed COVID-19 between January 2021 and April 2021 from two US centres. Patients self-administered 80 mg famotidine (n=28) or placebo (n=27) orally three times a day for 14 consecutive days. Endpoints were time to (primary) or rate of (secondary) symptom resolution, and resolution of inflammation (exploratory)., Results: Of 55 patients in the intention-to-treat group (median age 35 years (IQR: 20); 35 women (64%); 18 African American (33%); 14 Hispanic (26%)), 52 (95%) completed the trial, submitting 1358 electronic symptom surveys. Time to symptom resolution was not statistically improved (p=0.4). Rate of symptom resolution was improved for patients taking famotidine (p<0.0001). Estimated 50% reduction of overall baseline symptom scores were achieved at 8.2 days (95% CI: 7 to 9.8 days) for famotidine and 11.4 days (95% CI: 10.3 to 12.6 days) for placebo treated patients. Differences were independent of patient sex, race or ethnicity. Five self-limiting adverse events occurred (famotidine, n=2 (40%); placebo, n=3 (60%)). On day 7, fewer patients on famotidine had detectable interferon alpha plasma levels (p=0.04). Plasma immunoglobulin type G levels to SARS-CoV-2 nucleocapsid core protein were similar between both arms., Conclusions: Famotidine was safe and well tolerated in outpatients with mild to moderate COVID-19. Famotidine led to earlier resolution of symptoms and inflammation without reducing anti-SARS-CoV-2 immunity. Additional randomised trials are required., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

Aneuploid yeast cells are in a chronic state of proteotoxicity, yet do not constitutively induce the cytosolic unfolded protein response, or heat shock response (HSR) by heat shock factor 1 (Hsf1). Here, we demonstrate that an active environmental stress response (ESR), a hallmark of aneuploidy across different models, suppresses Hsf1 induction in models of single-chromosome gain. Furthermore, engineered activation of the ESR in the absence of stress was sufficient to suppress Hsf1 activation in euploid cells by subsequent heat shock while increasing thermotolerance and blocking formation of heat-induced protein aggregates. Suppression of the ESR in aneuploid cells resulted in longer cell doubling times and decreased viability in the presence of additional proteotoxicity. Last, we show that in euploids, Hsf1 induction by heat shock is curbed by the ESR. Strikingly, we found a similar relationship between the ESR and the HSR using an inducible model of aneuploidy. Our work explains a long-standing paradox in the field and provides new insights into conserved mechanisms of proteostasis with potential relevance to cancers associated with aneuploidy.

Background: A retrospective study was conducted to evaluate the role of distal radioulnar joint (DRUJ) effusion in aiding the diagnostic accuracy of central triangular fibrocartilage complex (TFCC) tears on non-contrast MRI., Methods: 89 consecutive patients who had undergone wrist arthroscopy for ulna sided wrist pain in our unit were identified and their preoperative imaging reviewed. Two consultant musculoskeletal Radiologists independently reported the presence or absence of a DRUJ effusion and or a TFCC tear. The inter-observer variability was calculated using weighted Kappa tests. Two by two tables were constructed to calculate the sensitivity and specificity of reported TFCC tear or DRUJ effusion on MRI in correctly diagnosing central TFCC tears identified at arthroscopy., Results: Sensitivity of MRI to report a TFCC tear was 0.56 and specificity was 0.79. Sensitivity increased to 0.89 if either a DRUJ effusion or TFCC tear were seen on MRI. When observed together, the presence of both a DRUJ effusion and a TFCC tear seen on the imaging lead to a sensitivity of 0.74 and PPV of 82% when compared to findings at arthroscopy. In the absence of both DRUJ effusion and TFCC tear, the specificity of MRI increased to 0.92. Agreement by the radiologists on the presence of DRUJ effusion was substantial (k value 0.67) and TFCC tear was moderate (k value 0.58)., Conclusion: The presence of DRUJ effusion on MRI can further improve sensitivity of MRI in diagnosing central TFCC tears. The sensitivity of detecting a central TFCC tear on MRI scan when both a DRUJ effusion and a TFCC tear were seen (0.74) is comparable to rates demonstrated on MRA meta-analysis results (0.78). Furthermore, considering the absence of both a DRUJ effusion and TFCC tear seen on MRI is useful in excluding the presence of a TFCC tear at arthroscopy.

p38 MAPKs play a central role in orchestrating the cellular response to stress and inflammation and in the regulation of myogenesis. Potent inhibitors of p38 MAPKs have been pursued as potential therapies for several disease indications due to their antiinflammatory properties, although none have been approved to date. Here, we provide a brief overview of p38 MAPKs, including their role in regulating myogenesis and their association with disease progression. Finally, we discuss targeting p38 MAPKs as a therapeutic approach for treating facioscapulohumeral muscular dystrophy and other muscular dystrophies by addressing multiple pathological mechanisms in skeletal muscle.

Aims: Debate continues regarding the optimum management of periprosthetic distal femoral fractures (PDFFs). This study aims to determine which operative treatment is associated with the lowest perioperative morbidity and mortality when treating low (Su type II and III) PDFFs comparing lateral locking plate fixation (LLP-ORIF) or distal femoral arthroplasty (DFA)., Methods: This was a retrospective cohort study of 60 consecutive unilateral (PDFFs) of Su types II (40/60) and III (20/60) in patients aged ≥ 60 years: 33 underwent LLP-ORIF (mean age 81.3 years (SD 10.5), BMI 26.7 (SD 5.5); 29/33 female); and 27 underwent DFA (mean age 78.8 years (SD 8.3); BMI 26.7 (SD 6.6); 19/27 female). The primary outcome measure was reoperation. Secondary outcomes included perioperative complications, calculated blood loss, transfusion requirements, functional mobility status, length of acute hospital stay, discharge destination and mortality. Kaplan-Meier survival analysis was performed. Cox multivariate regression analysis was performed to identify risk factors for reoperation after LLP-ORIF., Results: Follow-up was at mean 3.8 years (1.0 to 10.4). One-year mortality was 13% (8/60). Reoperation was more common following LLP-ORIF: 7/33 versus 0/27 (p = 0.008). Five-year survival for reoperation was significantly better following DFA; 100% compared to 70.8% (95% confidence interval (CI) 51.8% to 89.8%, p = 0.006). There was no difference for the endpoint mechanical failure (including radiological loosening); ORIF 74.5% (56.3 to 92.7), and DFA 78.2% (52.3 to 100, p = 0.182). Reoperation following LLP-ORIF was independently associated with medial comminution; hazard ratio (HR) 10.7 (1.45 to 79.5, p = 0.020). Anatomical reduction was protective against reoperation; HR 0.11 (0.013 to 0.96, p = 0.046). When inadequately fixed fractures were excluded, there was no difference in five-year survival for either reoperation (p = 0.156) or mechanical failure (p = 0.453)., Conclusion: Absolute reoperation rates are higher following LLP fixation of low PDFFs compared to DFA. Where LLP-ORIF was well performed with augmentation of medial comminution, there was no difference in survival compared to DFA. Though necessary in very low fractures, DFA should be used with caution in patients with greater life expectancies due to the risk of longer term aseptic loosening. Cite this article: Bone Joint J  2021;103-B(4):635-643.

Aims: This study aims to define the epidemiology of trauma presenting to a single centre providing all orthopaedic trauma care for a population of ∼ 900,000 over the first 40 days of the COVID-19 pandemic compared to that presenting over the same period one year earlier. The secondary aim was to compare this with population mobility data obtained from Google., Methods: A cross-sectional study of consecutive adult (> 13 years) patients with musculoskeletal trauma referred as either in-patients or out-patients over a 40-day period beginning on 5 March 2020, the date of the first reported UK COVID-19 death, was performed. This time period encompassed social distancing measures. This group was compared to a group of patients referred over the same calendar period in 2019 and to publicly available mobility data from Google., Results: Orthopaedic trauma referrals reduced by 42% (1,056 compared to 1,820) during the study period, and by 58% (405 compared to 967) following national lockdown. Outpatient referrals reduced by 44%, and inpatient referrals by 36%, and the number of surgeries performed by 36%. The regional incidence of traumatic injury fell from 5.07 (95% confidence interval (CI) 4.79 to 5.35) to 2.94 (95% CI 2.52 to 3.32) per 100,000 population per day. Significant reductions were seen in injuries related to sports and alcohol consumption. No admissions occurred relating to major trauma (Injury Severity Score > 16) or violence against the person. Changes in population mobility and trauma volume from baseline correlated significantly (Pearson's correlation 0.749, 95% CI 0.58 to 0.85, p < 0.001). However, admissions related to fragility fractures remained unchanged compared to the 2019 baseline., Conclusion: The profound changes in social behaviour and mobility during the early stages of the COVID-19 pandemic have directly correlated with a significant decrease in orthopaedic trauma referrals, but fragility fractures remained unaffected and provision for these patients should be maintained.Cite this article: Bone Joint Open 2020;1-6:182-189., Competing Interests: ICMJE COI statement: C. Scott reports editorial board membership of The Bone & Joint Journal and Bone & Joint Research, and consultancy and grants/grants pending from Stryker Orthopaedics, all of which are unrelated to this article. T. White reports consultancy from Acumed, and grants/grants pening from Acumed and Smith & Nephew, which are unrelated to this article. A. Duckworth reports grants from Scottish Government Quality Improvement Grant, Smith & Nephew, and Acumed, and book royalties from Elsevier and Taylor & Francis, all of which are unrelated to this article., (© 2020 Author(s) et al.)

Limitations associated with current bone grafting materials has necessitated the development of synthetic scaffolds that mimic the native tissue for bone repair. Scaffold parameters such as pore size, pore interconnectivity, fibre diameter, and fibre stiffness are crucial parameters of fibrous bone tissue engineering (BTE) scaffolds required to replicate the native environment. Optimum values vary with material, fabrication method and cell type. Melt electrowriting (MEW) provides precise control over extracellular matrix (ECM)-like fibrous scaffold architecture. The goal of this study was to fabricate and characterise poly-ε-caprolactone (PCL) fibrous scaffolds with 100, 200, and 300 μm pore sizes using MEW and determine the influence of pore size on human bone marrow stem cell (hMSC) adhesion, morphology, proliferation, mechanosignalling and osteogenesis. Each scaffold was fabricated with a fibre diameter of 4.01 ± 0.06 μm. The findings from this study highlight the enhanced osteogenic effects of controlled micro-scale fibre deposition using MEW, where the benefits of 100 μm square pores in comparison with larger pore sizes are illustrated, a pore size traditionally reported as a lower limit for osteogenesis. This suggests a lower pore size is optimal when hMSCs are seeded in a 3D ECM-like fibrous structure, with the 100 μm pore size optimal as it demonstrates the highest global stiffness, local fibre stiffness, highest seeding efficiency, maintains a spread cellular morphology, and significantly enhances hMSC collagen and mineral deposition. Similarly, this platform represents an effective in vitro model for the study of hMSC behaviour to determine the significant osteogenic benefits of controlling ECM-like fibrous BTE scaffold pore size using MEW.

Aneuploidy, a condition characterized by chromosome gains and losses, causes reduced fitness and numerous cellular stresses, including increased protein aggregation. Here, we identify protein complex stoichiometry imbalances as a major cause of protein aggregation in aneuploid cells. Subunits of protein complexes encoded on excess chromosomes aggregate in aneuploid cells, which is suppressed when expression of other subunits is coordinately altered. We further show that excess subunits are either degraded or aggregate and that protein aggregation is nearly as effective as protein degradation at lowering levels of excess proteins. Our study explains why proteotoxic stress is a universal feature of the aneuploid state and reveals protein aggregation as a form of dosage compensation to cope with disproportionate expression of protein complex subunits., (© 2019 Brennan et al.; Published by Cold Spring Harbor Laboratory Press.)

Phenotypic variability is a hallmark of diseases involving chromosome gains and losses, such as Down syndrome and cancer. Allelic variances have been thought to be the sole cause of this heterogeneity. Here, we systematically examine the consequences of gaining and losing single or multiple chromosomes to show that the aneuploid state causes non-genetic phenotypic variability. Yeast cell populations harboring the same defined aneuploidy exhibit heterogeneity in cell-cycle progression and response to environmental perturbations. Variability increases with degree of aneuploidy and is partly due to gene copy number imbalances, suggesting that subtle changes in gene expression impact the robustness of biological networks and cause alternate behaviors when they occur across many genes. As inbred trisomic mice also exhibit variable phenotypes, we further propose that non-genetic individuality is a universal characteristic of the aneuploid state that may contribute to variability in presentation and treatment responses of diseases caused by aneuploidy., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: We aimed to assess insulin sensitivity and other metabolic features of dippers and non-dippers among overweight middle-aged men., Methods: We studied 73 men (45.8 ± 5.3 years) who were overweight but normotensive. Participants were separated into dippers and non-dippers based on the magnitude of the nocturnal decline of blood pressure, with dippers experiencing an overnight decline ≥10% as per standard definition. Our study included 51 dippers and 22 non-dippers. All participants underwent 24-hour ambulatory blood pressure monitoring. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test; other assessments included carotid artery intima-media thickness (CIMT), body composition derived from dual-energy X-ray absorptiometry, lipid profiles, and a physical activity questionnaire., Results: Non-dippers had lower daytime systolic (-5.0mmHg; p=0.022) and diastolic (-3.3mmHg; p=0.035) blood pressure than dippers. Conversely, during sleep, non-dippers had higher systolic (+6.5mmHg; p=0.003) and diastolic (+5.6mmHg; p=0.001) blood pressure. In continuous associations, increasing CIMT was associated with decreasing systolic (p=0.012) and diastolic (p=0.042) dipping. Thus, non-dippers had CIMT that was 9% greater than that of dippers (749 vs 820μm; p=0.036). Importantly, there was no association between non-dipping status or the magnitude of the nocturnal dip with insulin sensitivity., Conclusions: Non-dippers had lower blood pressure in the daytime, but higher blood pressure in the night time compared to dippers. Non-dippers had increased CIMT, which suggests that normotensive men with a non-dipping ambulatory blood pressure profile may be at increased cardiovascular risk. However, it appears that the non-dipping profile is unrelated to dysfunction of glucose homeostasis in overweight normotensive men., (Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid analogues of the PVP/VA copolymer (N-vinylpyrrolidone and vinyl acetate). The predicted solubilities at 25 °C varied considerably depending on the method used. However, the three thermal analysis methods ranked the predicted solubilities in the same order, except for the felodipine-PVP system. Furthermore, the magnitude of the predicted solubilities from the recrystallization method and melting point depression method correlated well with the estimates based on the solubility in the liquid analogues, which suggests that this method can be used as an initial screening tool if a liquid analogue is available. The learnings of this important comparative study provided general guidance for the selection of the most suitable method(s) for the screening of drug-polymer solubility.

Background: Krill is an increasingly popular source of marine n-3 (ω-3) PUFA that is seen as a premium product. However, to our knowledge, the effect of krill-oil supplementation on insulin sensitivity in humans has not been reported., Objective: We assessed whether supplementation with a blend of krill and salmon (KS) oil [which is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] affects insulin sensitivity in overweight men., Design: The design was a randomized, double-blind, controlled crossover trial. A total of 47 men with a mean ± SD age of 46.5 ± 5.1 y, who were overweight [body mass index (in kg/m(2)) from 25 to 30] but otherwise healthy, received 5 1-g capsules of KS oil or a control (canola oil) for 8 wk and crossed over to another treatment after an 8-wk washout period. The primary outcome was insulin sensitivity assessed by using the Matsuda method from an oral-glucose-tolerance test. Secondary outcomes included lipid profiles, inflammatory markers, 24-h ambulatory blood pressure, and carotid artery intimamedia thickness., Results: Unexpectedly, insulin sensitivity (per the Matsuda index) was 14% lower with the KS oil than with the control oil (P = 0.049). A mediation analysis showed that, after controlling for the likely positive effects of blood EPA and DHA (i.e., the omega-3 index), the reduction in insulin sensitivity after KS-oil supplementation was more marked [27% lower than with the control oil (P = 0.009)]., Conclusions: Supplementation with a blend of KS oil is associated with decreased insulin sensitivity. Thus, krill-oil supplementation in overweight adults could exacerbate risk of diabetes and cardiovascular disease. This trial was prospectively registered at the Australian New Zealand Clinical Trials Registry as ACTRN12611000602921., (© 2015 American Society for Nutrition.)

Objective: To assess the effect of parental age at childbirth on insulin sensitivity and other metabolic outcomes in overweight middle-aged males., Methods: We studied 73 men aged 46.0±5.4 years, who were overweight (body mass index, BMI 25-30 kg/m(2) ) but otherwise healthy. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Other assessments included dual-energy X-ray absorptiometry-derived body composition, lipid profile, 24-hour ambulatory blood pressure, and carotid intima-media thickness. Maternal and paternal ages were highly correlated (r = 0.71; P < 0.0001), and the main parameter of interest in this study was the mean parental age at childbirth (MPAC), calculated as the average of maternal and paternal ages., Results: Increasing MPAC was associated with a continuous increase in insulin sensitivity (β = 0.193; P = 0.008), as well as reductions in insulin resistance (HOMA-IR; β = -0.064; P = 0.011), fasting insulin (β = -0.221; P = 0.018) and fasting glucose (β = -0.030; P = 0.033) concentrations. Increasing MPAC was also associated with reductions in night time systolic (β = -0.500; P = 0.020) and diastolic (β = -0.325; P = 0.047) blood pressure, as well as with improved (greater) nocturnal diastolic blood pressure dipping (β = 0.413; P = 0.046). Subgroup analyses on participants of European descent (n = 64) showed that increasing MPAC was associated with reduced carotid intima-media thickness (β = -0.008; P = 0.018) and lower low-density lipoprotein cholesterol concentrations (β = -0.042; P = 0.028)., Conclusions: Increasing parental age at childbirth was associated with a more favorable metabolic phenotype in overweight middle-aged males. However, it is unknown whether the effect was maternal, paternal, or both. Future studies on the effects of parental age at childbirth on the metabolism of males and females across the BMI range are required., (© 2014 Wiley Periodicals, Inc.)

The RNA chaperone Hfq fulfills important roles in small regulatory RNA (sRNA) function in many bacteria. Loss of Hfq in the dissimilatory metal reducing bacterium Shewanella oneidensis strain MR-1 results in slow exponential phase growth and a reduced terminal cell density at stationary phase. We have found that the exponential phase growth defect of the hfq mutant in LB is the result of reduced heme levels. Both heme levels and exponential phase growth of the hfq mutant can be completely restored by supplementing LB medium with 5-aminolevulinic acid (5-ALA), the first committed intermediate synthesized during heme synthesis. Increasing expression of gtrA, which encodes the enzyme that catalyzes the first step in heme biosynthesis, also restores heme levels and exponential phase growth of the hfq mutant. Taken together, our data indicate that reduced heme levels are responsible for the exponential growth defect of the S. oneidensis hfq mutant in LB medium and suggest that the S. oneidensis hfq mutant is deficient in heme production at the 5-ALA synthesis step.

We assessed whether omega-3 index (red blood cell concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) was associated with insulin sensitivity and other metabolic outcomes in 47 overweight men aged 46.5 ± 5.1 years. Participants were assessed twice, 16 weeks apart. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Linear associations were examined; stratified analyses were carried out with participants separated according to the omega-3 index: lower tertiles (LOI; n = 31) and highest tertile (HOI; n = 16). Increasing omega-3 index was correlated with higher insulin sensitivity (r = 0.23; p = 0.025), higher disposition index (r = 0.20; p = 0.054), and lower CRP concentrations (r = -0.39; p < 0.0001). Insulin sensitivity was 43% higher in HOI than in LOI men (Matsuda index 6.83 vs 4.78; p = 0.009). Similarly, HOI men had disposition index that was 70% higher (p = 0.013) and fasting insulin concentrations 25% lower (p = 0.038). HOI men displayed lower nocturnal systolic blood pressure (-6.0 mmHg; p = 0.025) and greater systolic blood pressure dip (14.7 vs 10.8%; p = 0.039). Men in the HOI group also had lower concentrations of CRP (41% lower; p = 0.033) and free fatty acids (21% lower, p = 0.024). In conclusion, higher omega-3 index is associated with increased insulin sensitivity and a more favourable metabolic profile in middle-aged overweight men.

We aimed to assess whether birth order affects metabolism and body composition in overweight middle-aged men. We studied 50 men aged 45.6 ± 5.5 years, who were overweight (BMI 27.5 ± 1.7 kg/m(2)) but otherwise healthy in Auckland, New Zealand. These included 26 first-borns and 24 second-borns. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Other assessments included DXA-derived body composition, lipid profiles, 24-hour ambulatory blood pressure, and carotid intima-media thickness. First-born men were 6.9 kg heavier (p = 0.013) and had greater BMI (29.1 vs 27.5 kg/m(2); p = 0.004) than second-borns. Insulin sensitivity in first-born men was 33% lower than in second-borns (4.38 vs 6.51; p = 0.014), despite adjustment for fat mass. There were no significant differences in ambulatory blood pressure, lipid profile or carotid intima-media thickness between first- and second-borns. Thus, first-born adults may be at a greater risk of metabolic and cardiovascular diseases.

Background: Hfq is an RNA chaperone protein that has been broadly implicated in sRNA function in bacteria. Here we describe the construction and characterization of a null allele of the gene that encodes the RNA chaperone Hfq in Shewanella oneidensis strain MR-1, a dissimilatory metal reducing bacterium., Results: Loss of hfq in S. oneidensis results in a variety of mutant phenotypes, all of which are fully complemented by addition of a plasmid-borne copy of the wild type hfq gene. Aerobic cultures of the hfq∆ mutant grow more slowly through exponential phase than wild type cultures, and hfq∆ cultures reach a terminal cell density in stationary phase that is ~2/3 of that observed in wild type cultures. We have observed a similar growth phenotype when the hfq∆ mutant is cultured under anaerobic conditions with fumarate as the terminal electron acceptor, and we have found that the hfq∆ mutant is defective in Cr(VI) reduction. Finally, the hfq∆ mutant exhibits a striking loss of colony forming units in extended stationary phase and is highly sensitive to oxidative stress induced by H2O2 or methyl viologen (paraquat)., Conclusions: The hfq mutant in S. oneidensis exhibits pleiotropic phenotypes, including a defect in metal reduction. Our results also suggest that hfq mutant phenotypes in S. oneidensis may be at least partially due to increased sensitivity to oxidative stress.

Background: Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans., Objective: To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men., Design: Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4 ± 5.5 years and BMI 28.0 ± 2.0 kg/m(2)) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness., Results: Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic β-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-α, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function., Conclusions: Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome.

Scurvy is a lethal but treatable disease that is rare in industrialized countries. Caused by vitamin C deficiency, it is most prevalent in persons of low socioeconomic status and smokers. Low levels of circulating vitamin C result in poor collagen fiber formation that, in turn, leads to demineralized bones, microfractures, and poor healing. Here we report a case of scurvy in a 5-year-old boy with normal radiographs in whom initial concern for leukemia based upon magnetic resonance imaging and clinical presentation led to a bone marrow biopsy revealing gelatinous transformation.

Aims: We aimed to assess the effects of psyllium supplementation on insulin sensitivity and other parameters of the metabolic syndrome in an at risk adolescent population., Methods: This study encompassed a participant-blinded, randomized, placebo-controlled, crossover trial. Subjects were 47 healthy adolescent males aged 15-16 years, recruited from secondary schools in lower socio-economic areas with high rates of obesity. Participants received 6 g/day of psyllium or placebo for 6 weeks, with a two-week washout before crossing over. Fasting lipid profiles, ambulatory blood pressure, auxological data, body composition, activity levels, and three-day food records were collected at baseline and after each 6-week intervention. Insulin sensitivity was measured by the Matsuda method using glucose and insulin values from an oral glucose tolerance test., Results: 45 subjects completed the study, and compliance was very high: 87% of participants took >80% of prescribed capsules. At baseline, 44% of subjects were overweight or obese. 28% had decreased insulin sensitivity, but none had impaired glucose tolerance. Fibre supplementation led to a 4% reduction in android fat to gynoid fat ratio (p = 0.019), as well as a 0.12 mmol/l (6%) reduction in LDL cholesterol (p = 0.042). No associated adverse events were recorded., Conclusions: Dietary supplementation with 6 g/day of psyllium over 6 weeks improves fat distribution and lipid profile (parameters of the metabolic syndrome) in an at risk population of adolescent males., Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12609000888268.

In this essay, we describe our experience with a sonographic technique utilizing the foramen magnum to more clearly define anatomy in the neonatal posterior fossa. This approach can be used as an additional problem-solving tool in neonates with post-hemorrhagic hydrocephalus and a variety of posterior fossa abnormalities. The foramen magnum view is easily mastered and produces diagnostic images with little additional scanning time.

Anti-CD20 monoclonal antibodies (mAbs) are classified into type I (rituximab-like) or type II (tositumomab-like) based on their ability to redistribute CD20 molecules in the plasma membrane and activate various effector functions. To compare type I and II mAbs directly in vivo and maximize Fc effector function, we selected and engineered mAbs with the same mouse IgG(2)a isotype and assessed their B-cell depleting activity in human CD20 transgenic mice. Despite being the same isotype, having similar affinity, opsonizing activity for phagocytosis, and in vivo half-life, the type II mAb tositumomab (B1) provided substantially longer depletion of B cells from the peripheral blood compared with the type I mAb rituximab (Rit m2a), and 1F5. This difference was also evident within the secondary lymphoid organs, in particular, the spleen. Failure to engage complement did not explain the efficacy of the type II reagents because type I mAbs mutated in the Fc domain (K322A) to prevent C1q binding still did not display equivalent efficacy. These results give support for the use of type II CD20 mAbs in human B-cell diseases.

A novel microfluidic approach for the quantification of reaction kinetics is presented. A three-dimensional finite difference numerical simulation was developed in order to extract quantitative kinetic information from fluorescence lifetime imaging experimental data. This approach was first utilized for the study of a fluorescence quenching reaction within a microchannel; the lifetime of a fluorophore was used to map the diffusion of a quencher across the microchannel. The approach was then applied to a more complex chemical reaction between a fluorescent amine and an acid chloride, via numerical simulation the bimolecular rate constant for this reaction was obtained.

Mitochondrial uncoupling protein 1 is usually associated with brown adipose tissue but has recently been discovered in rat and mouse thymus. We wished to establish whether there was a thermogenic role for UCP 1 in thymus and thus examined the effect of 5 weeks cold-acclimation on rat thymus tissue abundance, thymocyte oxygen consumption, thymus mitochondrial abundance, uncoupling protein 1 expression and function. We found that thymocytes from cold-acclimated rats had oxygen consumption rates 8 times less than those from rats held at room temperature and that thymocytes from cold-acclimated rats or rats kept at room temperature were noradrenaline insensitive. In addition, we found that thymus tissue or mitochondrial abundance was not increased after cold-acclimation. However uncoupling protein 1 expression per unit mass of mitochondria was increased after cold-acclimation, as determined by immunoblotting (approximately 1.7-fold) and GDP binding (approximately 1.5-fold). Consistent with our protein expression data, we also observed an increased, state 4 (approximately 1.5-fold), GDP-inhibitable (approximately 1.3-fold) and palmitate activatable (approximately 1.6-fold) oxygen consumption rates in isolated thymus mitochondria. However, extrapolation of our data showed that cold-acclimation only increased the amount of UCP 1 per gram of thymus tissue approximately 1.2-fold. Taken together, we conclude that UCP 1 does not have a thermogenic role in thymus.

We describe the application of wide-field frequency domain Fluorescence Lifetime Imaging Microscopy (FLIM) to imaging in microfluidic devices. FLIM is performed using low cost, intensity modulated Light Emitting Diodes (LEDs) for illumination. The use of lifetime imaging for quantitative analysis within such devices is demonstrated by mapping the molecular diffusion of iodide ions across a microchannel.

A surface-controlled dissolution of cylindrical solid particles model is applied to potassium carbonate, sodium bicarbonate and sodium carbonate in dimethylformamide at elevated temperatures. Previously published data for the dissolution of potassium carbonate is interpreted assuming a cylindrical rather than a spherical shape of the particles, the former representing a closer approximation to the true shape of the particles as revealed by scanning electron microscopy. The dissolution kinetics of sodium carbonate and sodium bicarbonate in dimethylformamide at 100 degrees C were investigated via monitoring of the deprotonation of 2-cyanophenol with dissolved solid to form the 2-cyanophenolate anion that was detected with UV-visible spectroscopy. From fitting of experimental results to theory, the dissolution rate constant, k, for the dissolutions of potassium carbonate, sodium bicarbonate and sodium carbonate in dimethylformamide at 100 degrees C were found to have the values of (1.0 +/- 0.1) x 10(-7) mol cm(-2) s(-1), (5.5 +/- 0.3) x 10(-9) mol cm(-2) s(-1) and (9.7 +/- 0.8) x 10(-9) mol cm(-2) s(-1), respectively.

In this paper we present a mathematical model for the surface-controlled dissolution of cylindrical solid particles. This is employed to interpret experimental data published previously for the dissolution of potassium bicarbonate in dimethylformamide at elevated temperatures. Significant kinetic differences in assuming cylindrical rather than spherical shapes are reported with the former representing a closer approximation to the true shape of the particles as revealed by scanning electron microscopy. From the fits of experimental data to the cylindrical model for the surface-controlled dissolution, the dissolution rate constant, k, for the dissolution of KHCO(3) in DMF was found to be (9.6 +/- 1.6) x 10(-9) mol cm(-2) s(-1) at 100 degrees C, and the activation energy for the dissolution was 34.5 kJ mol(-1) over the temperature range of 60-100 degrees C. Comparison between cylindrical and spherical dissolution theory highlights the importance of considering the particle shapes for realistic modeling of surface-controlled dissolution kinetics.

Understanding the mechanisms of solid-liquid systems is fundamental to the development and operation of processes for the production of agrochemicals and pharmaceuticals. The use of a strong inorganic base in an organic solvent, typically, potassium carbonate in dimethylformamide, is often used to facilitate the formation of a required anionic organic nucleophile. In this paper, the dissolution kinetics of potassium carbonate in dimethylformamide at elevated temperatures is studied in the presence of ultrasound, as revealed via monitoring of the deprotonation of 2-cyanophenol by dissolved K2CO3. Two independent experimental methods were employed; the loss of 2-cyanophenol was detected electrochemically at a platinum microdisk working electrode, and the formation of the 2-cyanophenolate anion was monitored via UV/visible spectroscopic analysis. The results were modeled by fitting the experimental data to a theoretical model for the surface-controlled dissolution of solid particles. The dissolution rate constant, k, for the dissolution of K2CO3 in DMF was found to have a value of (1.3 +/- 0.2) x 10(-7) mol cm(-2) s(-1) at 100 degrees C, and the activation energy for the dissolution was 44.2 +/- 0.4 kJ mol(-1) over the temperature range of 70-100 degrees C studied.

We present evidence that rat and mouse thymi contain mitochondrial uncoupling protein (UCP 1). Reverse transcriptase-PCR detected RNA transcripts for UCP 1 in whole thymus and in thymocytes. Furthermore, using antibodies to UCP 1 the protein was also detected in mitochondria isolated from whole thymus and thymocytes but not in thymus mitochondria from UCP 1 knock-out mice. Evidence for functional UCP 1 in thymus mitochondria was obtained by a comparative analysis with the kinetics of GDP binding in mitochondria from brown adipose tissue. Both tissues showed equivalent B(max) and K(D) values. In addition, a large component of the nonphosphorylating oxygen consumption by thymus mitochondria was inhibited by GDP and subsequently stimulated by addition of nanomolar concentrations of palmitate. UCP 1 was purified from thymus mitochondria by hydroxyapatite chromatography. The isolated protein was identified by peptide mass mapping and tandem mass spectrometry by using MALDI-TOF and LC-MS/MS, respectively. We conclude that the thymus contains a functioning UCP 1 that has the capacity to regulate metabolic flux and production of reactive oxygen-containing molecules in the thymus.

We present a mathematical model for the surface-controlled dissolution of solid particles. This is applied to the dissolution of a solid having different particle size distribution functions: those of a monodispersed solid containing particles of all one size, a two-size-particle distribution, and a Gaussian distribution of the particle sizes. The dissolution of potassium bicarbonate in dimethylformamide is experimentally studied indirectly at elevated temperatures. We monitor the dissolution via the homogeneous deprotonation of 2-cyanophenol by dissolved KHCO3. The loss of 2-cyanophenol was detected electrochemically at a platinum microdisk electrode, and separately, the formation of the 2-cyanophenolate anion was monitored via UV-visible spectroscopic analysis. The results presented show that the kinetics of the loss of 2-cyanophenol behaves on one hand as a homogeneous chemical process and on the other hand as a dissolution-rate-controlled process. Initially, predissolved KHCO3 in solution deprotonates the 2-cyanophenol and homogeneous reaction dominates the observed kinetics, and at longer times, the observed kinetics is controlled by the rate of KHCO3 dissolution. Modeling of the experimental results for the surface-controlled dissolution of KHCO3 in dimethylformamide (DMF) yielded a mean value for the dissolution rate constant, k, at elevated temperatures; k was found to have a value of (1.1 +/- 0.3) x 10(-8) mol cm(-2) s(-1) at 100 degrees C, and the activation energy for the dissolution was 34.4 +/- 0.4 kJ mol(-1) over the temperature range 60-100 degrees C.

AU-rich elements (AREs) located in the 3' UTRs of the messenger RNAs (mRNAs) of many mammalian early response genes promote rapid mRNA turnover. HuR, an RRM-containing RNA-binding protein, specifically interacts with AREs, stabilizing these mRNAs. HuR is primarily nucleoplasmic, but shuttles between the nucleus and the cytoplasm via a domain called HNS located between RRM2 and RRM3. We recently showed that HuR interacts with two protein ligands, pp32 and APRIL, which are also shuttling proteins, but rely on NES domains recognized by CRM1 for export. Here we show that heat shock induces increased association of HuR with pp32 and APRIL through protein-protein interactions and that these ligands partially colocalize with HuR in cytoplasmic foci. HuR associations with the hnRNP complex also increase, but through RNA links. CRM1 coimmunoprecipitates with HuR only after heat shock, and nuclear export of HuR becomes sensitive to leptomycin B, an inhibitor of CRM1. Export after heat shock requires the same domains of HuR (HNS and RRM3) that are essential for binding pp32 and APRIL. In situ hybridization and coimmunoprecipitation experiments show that LMB treatment blocks both hsp70 mRNA nuclear export and its cytoplasmic interaction with HuR after heat shock. Together, our results argue that upon heat shock, HuR switches its export pathway to that of its ligands pp32 and APRIL, which involves the nuclear export factor CRM1. HuR and its ligands may be instrumental in the nuclear export of heat-shock mRNAs.

An important mechanism of posttranscriptional gene regulation in mammalian cells is the rapid degradation of messenger RNAs (mRNAs) signaled by AU-rich elements (AREs) in their 3' untranslated regions. HuR, a ubiquitously expressed member of the Hu family of RNA-binding proteins related to Drosophila ELAV, selectively binds AREs and stabilizes ARE-containing mRNAs when overexpressed in cultured cells. This review discusses mRNA decay as a general form of gene regulation, decay signaled by AREs, and the role of HuR and its Hu-family relatives in antagonizing this mRNA degradation pathway. The influence of newly identified protein ligands to HuR on HuR function in both normal and stressed cells may explain how ARE-mediated mRNA decay is regulated in response to environmental change.

AU-rich elements (AREs) present in the 3' untranslated regions of many protooncogene, cytokine, and lymphokine messages target them for rapid degradation. HuR, a ubiquitously expressed member of the ELAV (embryonic lethal abnormal vision) family of RNA binding proteins, selectively binds AREs and stabilizes ARE-containing mRNAs in transiently transfected cells. Here, we identify four mammalian proteins that bind regions of HuR known to be essential for its ability to shuttle between the nucleus and the cytoplasm and to stabilize mRNA: SETalpha, SETbeta, pp32, and acidic protein rich in leucine (APRIL). Three have been reported to be protein phosphatase 2A inhibitors. All four ligands contain long, acidic COOH-terminal tails, while pp32 and APRIL share a second motif: rev-like leucine-rich repeats in their NH(2)-terminal regions. We show that pp32 and APRIL are nucleocytoplasmic shuttling proteins that interact with the nuclear export factor CRM1 (chromosomal region maintenance protein 1). The inhibition of CRM1 by leptomycin B leads to the nuclear retention of pp32 and APRIL, their increased association with HuR, and an increase in HuR's association with nuclear poly(A)+ RNA. Furthermore, transcripts from the ARE-containing c-fos gene are selectively retained in the nucleus, while the cytoplasmic distribution of total poly(A)+ RNA is not altered. These data provide evidence that interaction of its ligands with HuR modulate HuR's ability to bind its target mRNAs in vivo and suggest that CRM1 is instrumental in the export of at least some cellular mRNAs under certain conditions. We discuss the possible role of these ligands upstream of HuR in pathways that govern the stability of ARE-containing mRNAs.

AU-rich elements (AREs) located in the 3' untranslated region target the mRNAs encoding many protooncoproteins, cytokines, and lymphokines for rapid degradation. HuR, a ubiquitously expressed member of the embryonic lethal abnormal vision (ELAV) family of RNA-binding proteins, binds ARE sequences and selectively stabilizes ARE-containing reporter mRNAs when overexpressed in transiently transfected cells. HuR appears predominantly nucleoplasmic but has been shown to shuttle between the nucleus and cytoplasm via a novel shuttling sequence HNS. We report generation of a mouse monoclonal antibody 3A2 that both immunoblots and immunoprecipitates HuR protein; it recognizes an epitope located in the first of HuR's three RNA recognition motifs. This antibody was used to probe HuR interactions with mRNA before and after heat shock, a condition that has been reported to stabilize ARE-containing mRNAs. At 37 degrees C, approximately one-third of the cytoplasmic HuR appears polysome associated, and in vivo UV crosslinking reveals that HuR interactions with poly(A)(+) RNA are predominantly cytoplasmic rather than nuclear. This comprises evidence that HuR directly interacts with mRNA in vivo. After heat shock, 12-15% of HuR accumulates in discrete foci in the cytoplasm, but surprisingly the majority of HuR crosslinks instead to nuclear poly(A)(+) RNA, whose levels are dramatically increased in the stressed cells. This behavior of HuR differs from that of another ARE-binding protein, hnRNP D, which has been implicated as an effector of mRNA decay rather than mRNA stabilization and of the general pre-RNA-binding protein hnRNP A1. We interpret these differences to mean that the temporal association of HuR with ARE-containing mRNAs is different from that of these other two proteins.

A lactate clamp method has been developed to quantify the whole body lactate utilization in conscious, unstressed rats. Dichloroacetate (DCA), a known lactate utilization enhancer, was used to validate the method. Fasting blood lactate concentrations before the clamps were identical for DCA-treated (1 mmol/kg) and control groups (1.65 +/- 0.37 vs. 1.65 +/- 0.19 mM). The animals received a primed continuous lactate infusion for 90 min at variable rates to clamp the blood lactate concentration at 2 mM. The steady-state (60-90 min) lactate infusion rate, which represents the whole body lactate utilization in DCA-treated animals, was 144% higher than that in the control animals (13.2 +/- 1.0 vs. 5.4 +/- 1.1 mg . kg-1 . min-1; P < 0.001). The markedly increased lactate infusion rate indicates an enhanced lactate flux by DCA. To determine whether the increased lactate infusion by DCA reflected reduced endogenous lactate production, lactate production was measured. The results indicate that endogenous lactate production was not affected by DCA. In conclusion, the lactate clamp provides a sensitive and reliable method to assess lactate utilization in vivo, a dynamic measurement that may not be clearly demonstrated by blood lactate concentrations per se.

The kinetics of the dyeing of a dichlorotriazinyl-reactive dye, Procion Blue MX-R, with knitted cotton fabrics have been studied using a versatile technique based on a spectrochemical channel flow cell. A mechanism is derived where the simultaneous hydrolysis of the dye molecules, the physical binding of the hydrolyzed form, and the chemical fixation of the active form onto the fabric are taken into account. It is shown that the dye fixation to the fabric is controlled by a solid-liquid interfacial process that is first order with respect to the surface concentration of dye; however, the rate of this reaction is governed by the availability of sites for the adsorption of dye molecules on the fabric surface. Dyeing experiments are performed over a wide range of initial dye concentrations; supporting electrolyte concentrations and the kinetic parameters are reported. Atomic force microscopic studies indicate that mercerization pretreatment provides a disordered fiber surface which may offer additional sites for dye adsorption.