94 research outputs found

    Retro-1-oligonucleotide conjugates. Synthesis and biological evaluation

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    Addition of small molecule Retro-1 has been described to enhance antisense and splice switching oligonucleotides. With the aim of assessing the effect of covalently linking Retro-1 to the biologically active oligonucleotide, three different derivatives of Retro-1 were prepared that incorporated a phosphoramidite group, a thiol or a 1,3-diene, respectively. Retro-1-oligonucleotide conjugates were assembled both on-resin (coupling of the phosphoramidite) and from reactions in solution (Michael-type thiol-maleimide reaction and Diels-Alder cycloaddition). Splice switching assays with the resulting conjugates showed that they were active but that they provided little advantage over the unconjugated oligonucleotide in the well-known HeLa Luc705 reporter system

    Simultaneous cyclization and derivatization of peptides using cyclopentenediones

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    Unprotected linear peptides containing N-terminal cysteines and another cysteine residue can be simultaneously cyclized and derivatized using 2,2-disubstituted cyclopentenediones. High yields of cyclic peptide conjugates may be obtained in short reaction times using only a slight excess of the cyclopentenedione moiety under TEMPO catalysis and in the presence of LiCl

    Contemporary outcomes of vertebral artery injury

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    ObjectiveVertebral artery injury (VAI) associated with cervical trauma is being increasingly recognized with more aggressive screening. Disparate results from previous literature have led to uncertainty of the significance, natural history, and optimal therapy for VAI.MethodsTo understand the natural history and treatment outcomes from our experience, we performed a retrospective, single-center review from a level I trauma center for the previous 10 years of all VAI. Injuries were identified from search of an administrative trauma database, a resident-run working database, and all radiology dictations for the same period. All VAI were classified according to segmental involvement, Denver grading scale, and laterality. Analysis of associated injuries, demographics, neurologic outcome, mortality, length of stay, treatment plan, and follow-up imaging was also performed.ResultsFifty-one patients with VAI were identified from 2001 to 2011 from a total of 36,942 trauma admissions (0.13% incidence). Associated injuries were significant with an average New Injury Severity Score of 29.6. Penetrating trauma occurred in 14%. Cervical spine fracture was present in 88% with VAI. Diagnosis was obtained with computed tomographic angiography (CTA) in 95%. Screening was prompted by injury pattern or high-risk mechanism in all cases. Injuries classified according to the Denver grading scale were grade I = 24%, grade II = 35%, grade III = 4%, grade IV = 35%, and grade V = 2%. Distribution across segments included V1 = 18%, V2 = 67%, V3 = 31%, and V4 = 6%. Only one posterior circulation stroke was attributable to VAI. Overall mortality was 8%, with each mortality being associated with significant other organ injuries. Treatment rendered for VAI was antiplatelet therapy (50%), observation (31%), warfarin (17%), and stent (2%). There were no significant differences between treatment groups on any variable with the exception of body mass index (P = .047). Follow-up was obtained for 13% (n = 6) of survivors. The CTA demonstrated injury stability in four patients and resolution in two patients. Accuracy of the administrative trauma database was 53% compared with 96% for the resident-run working database.ConclusionsNeurologic sequelae attributable to VAI were rare. Grade of VAI or vertebral artery segment did not correlate with morbidity. We did not observe any differences in short-term outcomes between systemic anticoagulation and antiplatelet therapy. Of those patients seen at follow-up, injury resolution or stability was documented by CTA. A conservative approach with either observation or antithrombotic therapy is suggested. If the natural history of VAI includes a very low stroke rate, then therapies with a lower therapeutic index, such as systemic anticoagulation, in the severely injured trauma patient are not supported. Our search strategy urges awareness of the limitations of administrative databases for retrospective vascular study

    Regulation of vascular smooth muscle cell expression and function of matrix metalloproteinases is mediated by estrogen and progesterone exposure

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    ObjectivePostmenopausal women receiving hormone replacement therapy (HRT) have been reported to have more adverse outcomes after vascular reconstructions, including increased intimal hyperplasia development and bypass graft failure. HRT may be affecting the pathway contributing to intimal hyperplasia. An important component of this pathway involves matrix metalloproteinases (MMPs), implicated in vascular remodeling due to their ability to degrade components of the extracellular matrix. We hypothesize that estrogen (Est) and progesterone (Prog) upregulate the MMP pathway in vascular smooth muscle cells (VSMCs) thereby increasing MMP activity and function.Methods and ResultsVSMCs were incubated with Est (5 ng/mL), Prog (50 ng/mL), Est + Prog combination (Est/Prog), and/or doxycycline (40 μg/mL; Doxy). Using reverse transcriptase polymerase chain reaction (RT-PCR) analysis we have previously shown membrane type 1-MMP (MT1-MMP) messenger ribonucleic acid (mRNA) levels are significantly increased by Est. Here, Western blot analyses indicated MT1-MMP and MMP-2 protein levels, not tissue inhibitor of MMP-2 (TIMP-2), were increased in response to Est and Est/Prog (P < .05 vs control). In-gel zymography revealed that Est and Est/Prog resulted in increased MMP-2 activity (hormone groups, P < .05 vs control) with no significant difference among the hormone groups. VSMC migration was increased by 45 ± 14% in response to Est (P < .05 vs control), as measured using a modified Boyden chamber assay. Doxycycline significantly inhibited basal and Est/Prog-stimulated increases in MMP-2 activity (P < .05 vs control; P < .05 vs hormone groups), and partially blocked basal and hormonally stimulated migration (P < .05 vs control and Est).ConclusionEstrogen and progesterone affects the MMP pathway by increasing MMP-2 enzymatic activity, possibly via the upregulation of MT1-MMP expression without a corresponding increase in TIMP expression. This increased collagenase activity increases VSMC motility and their ability to migrate through a collagen type IV lattice. Est/Prog upregulation of MT1-MMP may contribute to the adverse effect of HRT on vascular interventions.Clinical RelevancePostmenopausal women receiving HRT have more adverse outcomes after vascular reconstructions, including intimal hyperplasia, restenosis, and decreased graft patency. MMPs play a major role in vascular remodeling due to their degradation of components of the basement membrane separating vascular cell layers. Specifically, MMP-2 has a strong affinity for collagen type IV degradation, and MT1-MMP is a transmembrane protein known to activate MMP-2 by proteolytic cleavage. Here we provide strong evidence for MT1-MMP's role in increased MMP-2 activity and increased cellular migration in VSMCs exposed to estrogen and progesterone. Manipulations of the MMP pathway specifically targeting MT1-MMP expression at the time of vascular interventions may improve outcomes in females receiving HRT

    Depression in Alzheimer''s Disease: A Delphi Consensus on Etiology, Risk Factors, and Clinical Management

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    Background: Alzheimer''s disease (AD) and other forms of dementia are among the most common causes of disability in the elderly. Dementia is often accompanied by depression, but specific diagnostic criteria and treatment approaches are still lacking. This study aimed to gather expert opinions on dementia and depressed patient management to reduce heterogeneity in everyday practice. Methods: Prospective, multicenter, 2-round Modified Delphi survey with 53 questions regarding risk factors (11), signs and symptoms (7), diagnosis (8), and treatment (27) of depression in dementia, with a particular focus on AD. The questionnaire was completed by a panel of 37 expert physicians in neurodegenerative diseases (19 neurologists, 17 psychiatrists, and 1 geriatrician). Results: Consensus was achieved in 40 (75.5%) of the items: agreement in 33 (62.3%) and disagreement in 7 (13.2%) of them. Among the most relevant findings, depression in the elderly was considered an early sign (prodromal) and/or a dementia risk factor, so routine cognitive check-ups in depressed patients should be adopted, aided by clinical scales and information from relatives. Careful interpretation of neuropsychological assessment must be carried out in patients with depression as it can undermine cognitive outcomes. As agreed, depression in early AD is characterized by somatic symptoms and can be differentiated from apathy by the presence of sadness, depressive thoughts and early-morning awakening. In later-phases, symptoms of depression would include sleep-wake cycle reversal, aggressive behavior, and agitation. Regardless of the stage of dementia, depression would accelerate its course, whereas antidepressants would have the opposite effect. Those that improve cognitive function and/or have a dual or multimodal mode of action were preferred: Duloxetine, venlafaxine/desvenlafaxine, vortioxetine, tianeptine, and mirtazapine. Although antidepressants may be less effective than in cognitively healthy patients, neither dosage nor treatment duration should differ. Anti-dementia cholinesterase inhibitors may have a synergistic effect with antidepressants. Exercise and psychological interventions should not be applied alone before any pharmacological treatment, yet they do play a part in improving depressive symptoms in demented patients. Conclusions: This study sheds light on several unresolved clinical challenges regarding depression in dementia patients. Further studies and specific recommendations for this comorbid patient population are still needed.

    Intramuscular Stimulation of Muscle Afferents Attains Prolonged Tremor Reduction in Essential Tremor Patients

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    This study proposes and clinically tests intramuscular electrical stimulation below motor threshold to achieve prolonged reduction of wrist flexion/extension tremor in Essential Tremor (ET) patients. The developed system consisted of an intramuscular thin-film electrode structure that included both stimulation and electromyography (EMG) recording electrodes, and a control algorithm for the timing of intramuscular stimulation based on EMG (closed-loop stimulation). Data were recorded from nine ET patients with wrist flexion/extension tremor recruited from the Gregorio Mara\uf1\uf3n Hospital (Madrid, Spain). Patients participated in two experimental sessions comprising: 1) sensory stimulation of wrist flexors/extensors via thin-film multichannel intramuscular electrodes; and 2) surface stimulation of the nerves innervating the same target muscles. For each session, four of these patients underwent random 60-s trials of two stimulation strategies for each target muscle: 1) selective and adaptive timely stimulation (SATS) - based on EMG of the antagonist muscle; and 2) continuous stimulation (CON) of target muscles. Two patients underwent SATS stimulation trials alone while the other three underwent CON stimulation trials alone in each session. Kinematics of wrist, elbow, and shoulder, together with clinical scales, were used to assess tremor before, right after, and 24 h after each session. Intramuscular SATS achieved, on average, 32% acute (during stimulation) tremor reduction on each trial, while continuous stimulation augmented tremorgenic activity. Furthermore, tremor reduction was significantly higher using intramuscular than surface stimulation. Prolonged reduction of tremor amplitude (24 h after the experiment) was observed in four patients. These results showed acute and prolonged (24 h) tremor reduction using a minimally invasive neurostimulation technology based on SATS of primary sensory afferents of wrist muscles. This strategy might open the possibility of an alternative therapeutic approach for ET patients

    Present and Future of Parkinson’s Disease in Spain: PARKINSON-2030 Delphi Project

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    Parkinson's disease (PD) is a chronic progressive and irreversible disease and the second most common neurodegenerative disease worldwide. In Spain, it affects around 120.000-150.000 individuals, and its prevalence is estimated to increase in the future. PD has a great impact on patients' and caregivers' lives and also entails a substantial socioeconomic burden. The aim of the present study was to examine the current situation and the 10-year PD forecast for Spain in order to optimize and design future management strategies. This study was performed using the modified Delphi method to try to obtain a consensus among a panel of movement disorders experts. According to the panel, future PD management will improve diagnostic capacity and follow-up, it will include multidisciplinary teams, and innovative treatments will be developed. The expansion of new technologies and studies on biomarkers will have an impact on future PD management, leading to more accurate diagnoses, prognoses, and individualized therapies. However, the socio-economic impact of the disease will continue to be significant by 2030, especially for patients in advanced stages. This study highlighted the unmet needs in diagnosis and treatment and how crucial it is to establish recommendations for future diagnostic and therapeutic management of PD

    Distributed Drug Discovery, Part 2: Global Rehearsal of Alkylating Agents for the Synthesis of Resin-Bound Unnatural Amino Acids and Virtual D3 Catalog Construction

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    Pharmacological Strategies for the Management of Levodopa-Induced Dyskinesia in Patients with Parkinson’s Disease

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