1,552 research outputs found

    Blood-Brain Barrier Penetration of Zolmitriptan—Modelling of Positron Emission Tomography Data

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    Positron emissiontomography (PET) with the drug radiolabelled allows a direct measurement of brain or other organ kinetics, information which can be essential in drug development. Usually, however, a PET-tracer is administered intravenously (i.v.), whereas the therapeutic drug is mostly given orally or by a different route to the PET-tracer. In such cases, a recalculation is needed to make the PET data representative for the alternative administration route. To investigate the blood-brain barrier penetration of a drug (zolmitriptan) using dynamic PET and by PK modelling quantify the brain concentration of the drug after the nasal administration of a therapeutic dose. [11C]Zolmitriptan at tracer dose was administered as a short i.v. infusion and the brain tissue and venous blood kinetics of [11C]zolmitriptan was measured by PET in 7 healthy volunteers. One PET study was performed before and one 30min after the administration of 5mg zolmitriptan as nasal spray. At each of the instances, the brain radioactivity concentration after subtraction of the vascular component was determined up to 90min after administration and compared to venous plasma radioactivity concentration after correction for radiolabelled metabolites. Convolution methods were used to describe the relationship between arterial and venous tracer concentrations, respectively between brain and arterial tracer concentration. Finally, the impulse response functions derived from the PET studies were applied on plasma PK data to estimate the brain zolmitriptan concentration after a nasal administration of a therapeutic dose. The studies shows that the PET data on brain kinetics could well be described as the convolution of venous tracer kinetics with an impulse response including terms for arterial-to-venous plasma and arterial-to-brain impulse responses. Application of the PET derived impulse responses on the plasma PK from nasal administration demonstrated that brain PK of zolmitriptan increased with time, achieving about 0.5mg/ml at 30min and close to a maximum of 1.5mg/ml after 2hr. A significant brain concentration was observed already after 5min. The data support the notation of a rapid brain availability of zolmitriptan after nasal administratio

    Avoidable mortality among parents whose children were placed in care in Sweden: A retrospective matched cohort study

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    Introduction Separation from one’s child can have significant consequences for parental health and well-being. Objectives and Approach We aimed to investigate whether parents whose children were placed in care had higher rates of avoidable (amenable and preventable) mortality. Data were obtained from the Swedish national registers. Mortality rates among parents whose children were placed in care between 1990 and 2012 (17 505 mothers, 18 286 fathers) were compared with a 5:1 matched cohort of parents whose children were not placed. We computed rate differences and hazard ratios of all-cause and avoidable mortality. Results When compared with parents who did not have a child placed in care, there were an additional 21 avoidable deaths per 10 000-person years among mothers and an additional 27 avoidable deaths per 10 000-person years among fathers whose children were placed in care. Among mothers, death due to preventable causes were 3·83 times greater (95% CI 2·82-5·21) and deaths due to amenable causes were 3·12 times greater (95% CI 2·07-4·69) for those whose children were placed in care. Among fathers, death due to preventable causes was 1·75 times greater (95% CI 1·41-2·16) and deaths due to amenable causes were 1·52 times greater (95% CI 1·08- 2·13) for those whose children were placed in care. Avoidable mortality rates were higher among mothers whose children were young when placed in care and parents whose children were all placed in care. Conclusion/Implications Mothers who had a young child placed and parents whose children were all placed in care are at much higher risk of avoidable mortality than parents whose children were not placed in care. Targeted public health interventions and more attentive health care could reduce risk of avoidable mortality in this group of parents

    Unidirectional Influx and Net Accumulation of PIB

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    The compound {N-methyl-[11C]}2-(4’-methylaminophenyl)-6-hydroxybenzothiazole, “PIB”, measured by positron emission tomography, has been demonstrated to image brain β-amyloid deposition in Alzheimer’s disease (AD). In the present study the benefit of measuring the PIB accumulation rate together with the unidirectional influx of PIB into the brain was investigated in healthy control subjects and patients with AD. In a monkey changes in the influx rate constant K1 of PIB closely followed changes in CBF, caused by alteration of PaCO2. In addition, K1 was high both in the monkey and in humans, suggesting that this parameter reflects CBF. Most AD patients studied showed clearly higher accumulation rate for PIB than the controls in cortical brain areas, while a few patients showed as low accumulation as the controls. K1 did not correlate with the accumulation rate, indicating that K1 for PIB provides extra information besides the accumulation rate

    Vulnerability to episodes of extreme weather: Butajira, Ethiopia, 1998–1999

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    BACKGROUND: During 1999-2000, great parts of Ethiopia experienced a period of famine which was recognised internationally. The aim of this paper is to characterise the epidemiology of mortality of the period, making use of individual, longitudinal population-based data from the Butajira demographic surveillance site and rainfall data from a local site. METHODS: Vital statistics and household data were routinely collected in a cluster sample of 10 sub-communities in the Butajira district in central Ethiopia. These were supplemented by rainfall and agricultural data from the national reporting systems. RESULTS: Rainfall was high in 1998 and well below average in 1999 and 2000. In 1998, heavy rains continued from April into October, in 1999 the small rains failed and the big rains lasted into the harvesting period. For the years 1998-1999, the mortality rate was 24.5 per 1,000 person-years, compared with 10.2 in the remainder of the period 1997-2001. Mortality peaks reflect epidemics of malaria and diarrhoeal disease. During these peaks, mortality was significantly higher among the poorer. CONCLUSIONS: The analyses reveal a serious humanitarian crisis with the Butajira population during 1998-1999, which met the CDC guideline crisis definition of more than one death per 10,000 per day. No substantial humanitarian relief efforts were triggered, though from the results it seems likely that the poorest in the farming communities are as vulnerable as the pastoralists in the North and East of Ethiopia. Food insecurity and reliance on subsistence agriculture continue to be major issues in this and similar rural communities. Epidemics of traditional infectious diseases can still be devastating, given opportunities in nutritionally challenged populations with little access to health care

    Paleogenomics. Genomic structure in Europeans dating back at least 36,200 years.

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    The origin of contemporary Europeans remains contentious. We obtained a genome sequence from Kostenki 14 in European Russia dating from 38,700 to 36,200 years ago, one of the oldest fossils of anatomically modern humans from Europe. We find that Kostenki 14 shares a close ancestry with the 24,000-year-old Mal'ta boy from central Siberia, European Mesolithic hunter-gatherers, some contemporary western Siberians, and many Europeans, but not eastern Asians. Additionally, the Kostenki 14 genome shows evidence of shared ancestry with a population basal to all Eurasians that also relates to later European Neolithic farmers. We find that Kostenki 14 contains more Neandertal DNA that is contained in longer tracts than present Europeans. Our findings reveal the timing of divergence of western Eurasians and East Asians to be more than 36,200 years ago and that European genomic structure today dates back to the Upper Paleolithic and derives from a metapopulation that at times stretched from Europe to central Asia.GeoGenetics members were supported by the Lundbeck Foundation and the Danish National Research Foundation (DNRF94). ASM was supported by the Swiss National Science Foundation (PBSKP3_143529). Research on the archaeological background by PRN was supported by a MC Career Integration Grant (322261).This is the accepted manuscript. The final version is available from Science at http://www.sciencemag.org/content/346/6213/1113.short

    The Scandinavian Sarcoma Group Central Register : 6,000 patients after 25 years of monitoring of referral and treatment of extremity and trunk wall soft-tissue sarcoma

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    Purpose - We wanted to examine the potential of the Scandinavian Sarcoma Group (SSG) Central Register, and evaluate referral and treatment practice for soft-tissue sarcomas in the extremities and trunk wall (STS) in the Nordic countries. Background - Based on incidence rates from the literature, 8,150 (7,000-9,300) cases of STS of the extremity and trunk wall should have been diagnosed in Norway, Finland, Iceland, and Sweden from 1987 through 2011. The SSG Register has 6,027 cases registered from this period, with 5,837 having complete registration of key variables. 10 centers have been reporting to the Register. The 5 centers that consistently report treat approximately 90% of the cases in their respective regions. The remaining centers have reported all the patients who were treated during certain time periods, but not for the entire 25-year period. Results - 59% of patients were referred to a sarcoma center untouched, i.e. before any attempt at open biopsy. There was an improvement from 52% during the first 5 years to 70% during the last 5 years. 50% had wide or better margins at surgery. Wide margins are now achieved less often than 20 years ago, in parallel with an increase in the use of radiotherapy. For the centers that consistently report, 97% of surviving patients are followed for more than 4 years. Metastasis-free survival (MFS) increased from 67% to 73% during the 25-year period. Interpretation - The Register is considered to be representative of extremity and trunk wall sarcoma disease in the population of Scandinavia, treated at the reporting centers. There were no clinically significant differences in treatment results at these centers.Peer reviewe

    Pharmacodynamic evaluation and safety assessment of treatment with antibodies to serum amyloid P component in patients with cardiac amyloidosis: an open-label Phase 2 study and an adjunctive immuno-PET imaging study.

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    BACKGROUND: In a Phase I study treatment with the serum amyloid P component (SAP) depleter miridesap followed by monoclonal antibody to SAP (dezamizumab) showed removal of amyloid from liver, spleen and kidney in patients with systemic amyloidosis. We report results from a Phase 2 study and concurrent immuno-positron emission tomography (PET) study assessing efficacy, pharmacodynamics, pharmacokinetics, safety and cardiac uptake (of dezamizumab) following the same intervention in patients with cardiac amyloidosis. METHODS: Both were uncontrolled open-label studies. After SAP depletion with miridesap, patients received ≤ 6 monthly doses of dezamizumab in the Phase 2 trial (n = 7), ≤ 2 doses of non-radiolabelled dezamizumab plus [89Zr]Zr-dezamizumab (total mass dose of 80 mg at session 1 and 500 mg at session 2) in the immuno-PET study (n = 2). Primary endpoints of the Phase 2 study were changed from baseline to follow-up (at 8 weeks) in left ventricular mass (LVM) by cardiac magnetic resonance imaging and safety. Primary endpoint of the immuno-PET study was [89Zr]Zr-dezamizumab cardiac uptake assessed via PET. RESULTS: Dezamizumab produced no appreciable or consistent reduction in LVM nor improvement in cardiac function in the Phase 2 study. In the immuno-PET study, measurable cardiac uptake of [89Zr]Zr-dezamizumab, although seen in both patients, was moderate to low. Uptake was notably lower in the patient with higher LVM. Treatment-associated rash with cutaneous small-vessel vasculitis was observed in both studies. Abdominal large-vessel vasculitis after initial dezamizumab dosing (300 mg) occurred in the first patient with immunoglobulin light chain amyloidosis enrolled in the Phase 2 study. Symptom resolution was nearly complete within 24 h of intravenous methylprednisolone and dezamizumab discontinuation; abdominal computed tomography imaging showed vasculitis resolution by 8 weeks. CONCLUSIONS: Unlike previous observations of visceral amyloid reduction, there was no appreciable evidence of amyloid removal in patients with cardiac amyloidosis in this Phase 2 trial, potentially related to limited cardiac uptake of dezamizumab as demonstrated in the immuno-PET study. The benefit-risk assessment for dezamizumab in cardiac amyloidosis was considered unfavourable after the incidence of large-vessel vasculitis and development for this indication was terminated. Trial registration NCT03044353 (2 February 2017) and NCT03417830 (25 January 2018)

    The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

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    BACKGROUND: Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. METHODS: Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. RESULTS: Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. CONCLUSIONS: The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts
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