89 research outputs found

    Lithium alters brain activation in bipolar disorder in a task- and state-dependent manner: an fMRI study

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    BACKGROUND: It is unknown if medications used to treat bipolar disorder have effects on brain activation, and whether or not any such changes are mood-independent. METHODS: Patients with bipolar disorder who were depressed (n = 5) or euthymic (n = 5) were examined using fMRI before, and 14 days after, being started on lithium (as monotherapy in 6 of these patients). Patients were examined using a word generation task and verbal memory task, both of which have been shown to be sensitive to change in previous fMRI studies. Differences in blood oxygenated level dependent (BOLD) magnitude between the pre- and post-lithium results were determined in previously defined regions of interest. Severity of mood was determined by the Hamilton Depression Scale for Depression (HAM-D) and the Young mania rating scale (YMRS). RESULTS: The mean HAM-D score at baseline in the depressed group was 15.4 ± 0.7, and after 2 weeks of lithium it was 11.0 ± 2.6. In the euthymic group it was 7.6 ± 1.4 and 3.2 ± 1.3 respectively. At baseline mean BOLD signal magnitude in the regions of interest for the euthymic and depressed patients were similar in both the word generation task (1.56 ± 0.10 and 1.49 ± 0.10 respectively) and working memory task (1.02 ± 0.04 and 1.12 ± 0.06 respectively). However, after lithium the mean BOLD signal decreased significantly in the euthymic group in the word generation task only (1.56 ± 0.10 to 1.00 ± 0.07, p < 0.001). Post-hoc analysis showed that these differences were statistically significant in Broca's area, the left pre-central gyrus, and the supplemental motor area. CONCLUSION: This is the first study to examine the effects of lithium on brain activation in bipolar patients. The results suggest that lithium has an effect on euthymic patients very similar to that seen in healthy volunteers. The same effects are not seen in depressed bipolar patients, although it is uncertain if this lack of change is linked to the lack of major improvements in mood in this group of patients. In conclusion, this study suggests that lithium may have effects on brain activation that are task- and state-dependent. Given the small study size and the mildness of the patient's depression these results require replication

    Association energetics of cross-reactive and specific antibodies

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    HyHEL-8, HyHEL-10, and HyHEL-26 (HH8, HH10, and HH26, respectively) are murine monoclonal IgG1 antibodies which share over 90% variable-region amino acid sequence identity and recognize identical structurally characterized epitopes on hen egg white lysozyme (HEL). Previous immunochemical and surface plasmon resonance-based studies have shown that these antibodies differ widely in their tolerance of mutations in the epitope. While HH8 is the most cross-reactive, HH26 is rigidified by a more extensive network of intramolecular salt links and is highly specific, with both association and dissociation rates strongly affected by epitope mutations. HH10 is of intermediate specificity, and epitope mutations produce changes primarily in the dissociation rate. Calorimetric characterization of the association energetics of these three antibodies with the native antigen HEL and with Japanese quail egg white lysozyme (JQL), a naturally occurring avian variant, shows that the energetics of interaction correlate with cross-reactivity and specificity. These results suggest that the greater cross-reactivity of HH8 may be mediated by a combination of conformational flexibility and less specific intermolecular interactions. Thermodynamic calculations suggest that upon association HH8 incurs the largest configurational entropic penalty and also the smallest loss of enthalpic driving force with variant antigen. Much smaller structural perturbations are expected in the formation of the less flexible HH26 complex, and the large loss of enthalpic driving force observed with variant antigen reflects its specificity. The observed thermodynamic parameters correlate well with the observed functional behavior of the antibodies and illustrate fundamental differences in thermodynamic characteristics between cross-reactive and specific molecular recognition

    X-ray and optical monitoring of the peculiar source 4U 1700+24/V934 Her

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    (Abridged) We report on ASCA and BeppoSAX observations of the X-ray source 4U 1700+24 and on (quasi-)simultaneous spectroscopy of its optical counterpart, V934 Her, from the Loiano 1.5-meter telescope. Archival ROSAT and RXTE data as well as the RXTE ASM light curve of 4U 1700+24 are also analyzed along with a 1985 EXOSAT pointing. The optical spectra are typical of a M2 III star; a revised distance to the object of ~400 pc is inferred. While these spectra do not show either any change between the two epochs or any peculiar feature, the X-ray spectra reveal a complex and long-term variable shape, with a clear soft excess. The X-ray spectral properties of the source are best described by a thermal Comptonization spectrum plus a soft energy(<1 keV) excess, which can be modeled with a blackbody emission with kT_BB ~ 1 keV; the latter component is not detected at the lowest source flux levels. The ratio between the two components varies substantially with the source flux. The X-ray emission from the object appears to become harder as its luminosity increases, and the RXTE data acquired during an outburst occurred during Fall 1997 display a hard tail detected up to 100 keV. Apart from erratic shot-noise variability on timescales of tens to thousands of seconds, no significant pulsations or QPOs are found from the timing analysis of the X-ray light curves. With the new distance determination, the 2-10 keV X-ray luminosity range spanned in the considered observations lies between ~2x10^32 and ~1x10^34 erg/s. All this allows us to suggest a scenario consisting of a wide binary system in which a neutron star accretes matter from the wind of an M giant.Comment: 14 pages, 5 figures, to be published on Astronomy & Astrophysics, Main Journa

    Change in Blood Pressure Variability Among Treated Elderly Hypertensive Patients and Its Association With Mortality

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    Background: Information is scarce regarding effects of antihypertensive medication on blood pressure variability (BPV) and associated clinical outcomes. We examined whether antihypertensive treatment changes BPV over time and whether such change (decline or increase) has any association with long-term mortality in an elderly hypertensive population. Methods and Results: We used data from a subset of participants in the Second Australian National Blood Pressure study (n=496) aged ≥65 years who had 24-hour ambulatory blood pressure recordings at study entry (baseline) and then after a median of 2 years while on treatment (follow-up). Weighted day-night systolic BPV was calculated for both baseline and follow-up as a weighted mean of daytime and nighttime blood pressure standard deviations. The annual rate of change in BPV over time was calculated from these BPV estimates. Furthermore, we classified both BPV estimates as high and low based on the baseline median BPV value and then classified BPV changes into stable: low BPV, stable: high BPV, decline: high to low, and increase: low to high. We observed an annual decline (mean±SD: −0.37±1.95; 95% CI, −0.54 to −0.19; P<0.001) in weighted day-night systolic BPV between baseline and follow-up. Having constant stable: high BPV was associated with an increase in all-cause mortality (hazard ratio: 3.03; 95% CI, 1.67–5.52) and cardiovascular mortality (hazard ratio: 3.70; 95% CI, 1.62–8.47) in relation to the stable: low BPV group over a median 8.6 years after the follow-up ambulatory blood pressure monitoring. Similarly, higher risk was observed in the decline: high to low group. Conclusions: Our results demonstrate that in elderly hypertensive patients, average BPV declined over 2 years of follow-up after initiation of antihypertensive therapy, and having higher BPV (regardless of any change) was associated with increased long-term mortality

    CACHE (Critical Assessment of Computational Hit-finding Experiments): A public–private partnership benchmarking initiative to enable the development of computational methods for hit-finding

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    One aspirational goal of computational chemistry is to predict potent and drug-like binders for any protein, such that only those that bind are synthesized. In this Roadmap, we describe the launch of Critical Assessment of Computational Hit-finding Experiments (CACHE), a public benchmarking project to compare and improve small-molecule hit-finding algorithms through cycles of prediction and experimental testing. Participants will predict small-molecule binders for new and biologically relevant protein targets representing different prediction scenarios. Predicted compounds will be tested rigorously in an experimental hub, and all predicted binders as well as all experimental screening data, including the chemical structures of experimentally tested compounds, will be made publicly available and not subject to any intellectual property restrictions. The ability of a range of computational approaches to find novel binders will be evaluated, compared and openly published. CACHE will launch three new benchmarking exercises every year. The outcomes will be better prediction methods, new small-molecule binders for target proteins of importance for fundamental biology or drug discovery and a major technological step towards achieving the goal of Target 2035, a global initiative to identify pharmacological probes for all human proteins. [Figure not available: see fulltext.

    Searches for the Shell Swept up by the Stellar Wind from Cyg OB2

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    We investigated the kinematics of ionized gas in an extended (20 degrees by 15 degrees) region containing the X-ray Superbubble in Cygnus with the aim of finding the shell swept up by a strong wind from Cyg OB2. H-alpha observations were carried out with high angular and spectral resolutions using a Fabry-Perot interferometer attached to the 125-cm telescope at the Crimean Observatory of the Sternberg Astronomical Institute. We detected high-velocity gas motions, which could result from the expansion of the hypothetical shell at a velocity of 25-50 km/s. Given the number of OB stars increased by Knoedlseder (2000) by an order of magnitude, Cyg OB2 is shown to possess a wind that is strong enough [Lw ~= (1-2)x10^39 erg/s] to produce a shell comparable in size to the X-ray Superbubble and to a giant system of optical filaments. Based on our measurements and on X-ray and infrared observations, we discuss possible observational manifestations of the shell swept up by the wind.Comment: 14 pages, Astronomy Letter

    Modulation of the surface proteome through multiple ubiquitylation pathways in African Trypanosomes

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    Recently we identified multiple suramin-sensitivity genes with a genome wide screen in Trypanosoma brucei that includes the invariant surface glycoprotein ISG75, the adaptin-1 (AP-1) complex and two deubiquitylating enzymes (DUBs) orthologous to ScUbp15/HsHAUSP1 and pVHL-interacting DUB1 (type I), designated TbUsp7 and TbVdu1, respectively. Here we have examined the roles of these genes in trafficking of ISG75, which appears key to suramin uptake. We found that, while AP-1 does not influence ISG75 abundance, knockdown of TbUsp7 or TbVdu1 leads to reduced ISG75 abundance. Silencing TbVdu1 also reduced ISG65 abundance. TbVdu1 is a component of an evolutionarily conserved ubiquitylation switch and responsible for rapid receptor modulation, suggesting similar regulation of ISGs in T. brucei. Unexpectedly, TbUsp7 knockdown also blocked endocytosis. To integrate these observations we analysed the impact of TbUsp7 and TbVdu1 knockdown on the global proteome using SILAC. For TbVdu1, ISG65 and ISG75 are the only significantly modulated proteins, but for TbUsp7 a cohort of integral membrane proteins, including the acid phosphatase MBAP1, that is required for endocytosis, and additional ISG-related proteins are down-regulated. Furthermore, we find increased expression of the ESAG6/7 transferrin receptor and ESAG5, likely resulting from decreased endocytic activity. Therefore, multiple ubiquitylation pathways, with a complex interplay with trafficking pathways, control surface proteome expression in trypanosomes

    Target 2035-update on the quest for a probe for every protein

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    Twenty years after the publication of the first draft of the human genome, our knowledge of the human proteome is still fragmented. The challenge of translating the wealth of new knowledge from genomics into new medicines is that proteins, and not genes, are the primary executers of biological function. Therefore, much of how biology works in health and disease must be understood through the lens of protein function. Accordingly, a subset of human proteins has been at the heart of research interests of scientists over the centuries, and we have accumulated varying degrees of knowledge about approximately 65% of the human proteome. Nevertheless, a large proportion of proteins in the human proteome (∼35%) remains uncharacterized, and less than 5% of the human proteome has been successfully targeted for drug discovery. This highlights the profound disconnect between our abilities to obtain genetic information and subsequent development of effective medicines. Target 2035 is an international federation of biomedical scientists from the public and private sectors, which aims to address this gap by developing and applying new technologies to create by year 2035 chemogenomic libraries, chemical probes, and/or biological probes for the entire human proteome

    Cost-effectiveness of robot-assisted radical cystectomy vs open radical cystectomy for patients with bladder cancer

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    Importance The value to payers of robot-assisted radical cystectomy with intracorporeal urinary diversion (iRARC) when compared with open radical cystectomy (ORC) for patients with bladder cancer is unclear. Objectives To compare the cost-effectiveness of iRARC with that of ORC. Design, Setting, and Participants This economic evaluation used individual patient data from a randomized clinical trial at 9 surgical centers in the United Kingdom. Patients with nonmetastatic bladder cancer were recruited from March 20, 2017, to January 29, 2020. The analysis used a health service perspective and a 90-day time horizon, with supplementary analyses exploring patient benefits up to 1 year. Deterministic and probabilistic sensitivity analyses were undertaken. Data were analyzed from January 13, 2022, to March 10, 2023. Interventions Patients were randomized to receive either iRARC (n = 169) or ORC (n = 169). Main Outcomes and Measures Costs of surgery were calculated using surgery timings and equipment costs, with other hospital data based on counts of activity. Quality-adjusted life-years were calculated from European Quality of Life 5-Dimension 5-Level instrument responses. Prespecified subgroup analyses were undertaken based on patient characteristics and type of diversion. Results A total of 305 patients with available outcome data were included in the analysis, with a mean (SD) age of 68.3 (8.1) years, and of whom 241 (79.0%) were men. Robot-assisted radical cystectomy was associated with statistically significant reductions in admissions to intensive therapy (6.35% [95% CI, 0.42%-12.28%]), and readmissions to hospital (14.56% [95% CI, 5.00%-24.11%]), but increases in theater time (31.35 [95% CI, 13.67-49.02] minutes). The additional cost of iRARC per patient was £1124 (95% CI, −£576 to £2824 [US 1622(951622 (95% CI, −831 to 4075)])withanassociatedgaininquality−adjustedlife−yearsof0.01124(954075)]) with an associated gain in quality-adjusted life-years of 0.01124 (95% CI, 0.00391-0.01857). The incremental cost-effectiveness ratio was £100 008 (US 144 312) per quality-adjusted life-year gained. Robot-assisted radical cystectomy had a much higher probability of being cost-effective for subgroups defined by age, tumor stage, and performance status. Conclusions and Relevance In this economic evaluation of surgery for patients with bladder cancer, iRARC reduced short-term morbidity and some associated costs. While the resulting cost-effectiveness ratio was in excess of thresholds used by many publicly funded health systems, patient subgroups were identified for which iRARC had a high probability of being cost-effective
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