604 research outputs found

    Growth-Deficient Mycobacteria in Patients with AIDS: Diagnosis by Analysis of DNA Amplified from Blood or Tissue

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    Amplification and sequencing of mycobacterial ribosomal RNA genes (16S rDNA) may permit the detection of growth-deficient species (i.e., those exhibiting no growth or those whose growth is delayed for more than 12 weeks). Of blood samples from 26 patients with AIDS and a liver sample from one additional AIDS patient, three samples (two of blood and the one of liver) were positive by polymerase chain reaction only; cultures of these three samples remained negative for more than 12 weeks. Analysis of amplified 16S rDNA from blood revealed a sequence characteristic of Mycobacterium genavense in the first case, in which one of many previous blood cultures had also been positive for M. genavense. The sequences found in the second and third cases were characteristic of Mycobacterium avium. The sample from the second patient was a liver biopsy specimen in which acid-fast bacilli were visualized; the culture of this specimen yielded M. avium after 7 months. The third sample was a blood sample from a patient in whom a relapse of treated M. avium infection was suspected. These results indicate that amplification and sequencing of mycobacterial 16S rDNA may permit early diagnosis and provide a rationale for treatment of infections due to growth-deficient mycobacteri

    Substance Misuse Education for Physicians: Why Older People are Important.

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    This perspective article focuses on the need for training and education for undergraduate medical students on substance-related disorders, and describes initiatives undertaken in the United Kingdom (UK), Netherlands, United States (US), and Norway to develop the skills, knowledge, and attitudes needed by future doctors to treat patients adequately. In addition, we stress that in postgraduate training, further steps should be taken to develop Addiction Medicine as a specialized and transverse medical domain. Alcohol use disorder is a growing public health problem in the geriatric population, and one that is likely to continue to increase as the baby boomer generation ages. Prescription drug misuse is a major concern, and nicotine misuse remains problematic in a substantial minority. Thus, Addiction Medicine training should address the problems for this specific population. In recent years, several countries have started an Addiction Medicine specialty. Although addiction psychiatry has been a subspecialty in the UK and US for more than 20 years, in most countries it has been a more recent development. Additional courses on addiction should be integrated into the curriculum at both undergraduate and postgraduate levels, as well as form part of the continuous training of other medical specialists. It is recommended that further research and mapping of what is currently taught in medical programs be undertaken, so as to enhance medical education in addiction and improve treatment services

    Limiting factors in sub-10 nm scanning-electron-beam lithography

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    Achieving the highest possible resolution using scanning-electron-beam lithography (SEBL) has become an increasingly urgent problem in recent years, as advances in various nanotechnology applications [ F. S. Bates and G. H. Fredrickson, Annu. Rev. Phys. Chem. 41, 525 (1990) ; Black et al., IBM J. Res. Dev. 51, 605 (2007) ; Yang et al., J. Chem. Phys. 116, 5892 (2002) ] have driven demand for feature sizes well into the sub-10 nm domain, close to the resolution limit of the current generation of SEBL processes. In this work, the authors have used a combination of calculation, modeling, and experiment to investigate the relative effects of resist contrast, beam scattering, secondary electron generation, system spot size, and metrology limitations on SEBL process resolution. In the process of investigating all of these effects, they have also successfully yielded dense structures with a pitch of 12 nm at voltages as low as 10 keV

    Epidemiology of chronic inflammatory demyelinating polyradiculoneuropathy in The Netherlands

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    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare but disabling disorder that often requires long‐term immunomodulatory treatment. Background incidence rates and prevalence and risk factors for developing CIDP are still poorly defined. In the current study, we used a longitudinal population‐based cohort study in The Netherlands to assess these rates and demographic factors and comorbidity associated with CIDP. We determined the incidence rate and prevalence of CIDP between 2008 and 2017 and the occurrence of potential risk factors in a retrospective Dutch cohort study using the Integrated Primary Care Information (IPCI) database. Cases were defined as CIDP if the diagnosis of CIDP was described in the electronic medical file. In a source population of 928 030 persons with a contributing follow‐up of 3 525 686 person‐years, we identified 65 patients diagnosed with CIDP. The overall incidence rate was 0.68 per 100 000 person‐years (95% CI 0.45‐0.99). The overall prevalence was 7.00 per 100 000 individuals (95% CI 5.41‐8.93). The overall incidence rate was higher in men compared to woman (IRR 3.00, 95% CI 1.27‐7.11), and higher in elderly of 50 years or older compared with people <50 years of age (IRR 17 95% CI 4‐73). Twenty percent of CIDP cases had DM and 9% a co‐existing other auto‐immune disease. These background rates are important to monitor changes in the frequency of CIDP following infectious disease outbreaks, identify potential risk factors, and to estimate the social and economic burden of CIDP

    A new neuropsychological instrument measuring effects of age and drugs on fitness to drive: development, reliability, and validity of MedDrive

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    Background: Current guidelines underline the limitations of existing instruments to assess fitness to drive and the poor adaptability of batteries of neuropsychological tests in primary care settings. Aims: To provide a free, reliable, transparent computer based instrument capable of detecting effects of age or drugs on visual processing and cognitive functions. Methods: Relying on systematic reviews of neuropsychological tests and driving performances, we conceived four new computed tasks measuring: visual processing (Task1), movement attention shift (Task2), executive response, alerting and orientation gain (Task3), and spatial memory (Task4). We then planned five studies to test MedDrive's reliability and validity. Study-1 defined instructions and learning functions collecting data from 105 senior drivers attending an automobile club course. Study-2 assessed concurrent validity for detecting minor cognitive impairment (MCI) against useful field of view (UFOV) on 120 new senior drivers. Study-3 collected data from 200 healthy drivers aged 20-90 to model age related normal cognitive decline. Study-4 measured MedDrive's reliability having 21 healthy volunteers repeat tests five times. Study-5 tested MedDrive's responsiveness to alcohol in a randomised, double-blinded, placebo, crossover, dose-response validation trial including 20 young healthy volunteers. Results: Instructions were well understood and accepted by all senior drivers. Measures of visual processing (Task1) showed better performances than the UFOV in detecting MCI (ROC 0.770 vs. 0.620; p=0.048). MedDrive was capable of explaining 43.4% of changes occurring with natural cognitive decline. In young healthy drivers, learning effects became negligible from the third session onwards for all tasks except for dual tasking (ICC=0.769). All measures except alerting and orientation gain were affected by blood alcohol concentrations. Finally, MedDrive was able to explain 29.3% of potential causes of swerving on the driving simulator. Discussion and conclusions: MedDrive reveals improved performances compared to existing computed neuropsychological tasks. It shows promising results both for clinical and research purposes

    Cannabinoids for behavioral symptoms in severe dementia: Safety and feasibility in a long-term pilot observational study in nineteen patients.

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    The management of behavioral symptoms and rigidity in patients with dementia constitutes a significant challenge. Short-term studies suggest an interest in the use of medical cannabis, but long-term data are lacking. The objective of this study was to investigate the feasibility and long-term safety of administering tetrahydrocannabinol/cannabidiol (THC/CBD) treatment as an additional drug to a poly medicated population with severe dementia, evaluate clinical improvements, and collect information on the pharmacokinetics of cannabinoids and possible drug-drug interactions. A prospective observational study of patients with severe dementia living in a long-term care home to whom the physicians had prescribed a medical cannabis treatment. Data were collected over 2 years. We assessed the changes in medical cannabis dosages, safety parameters, variations in neuropsychiatric problems, agitation, rigidity, the most invalidating daily activity, and disabling behavior trouble scores. We evaluated the pharmacokinetics of cannabinoids by measuring plasma levels and analyzing the enzymatic activity. We assessed 19 patients (81.4 years-17 women and two men) receiving an average of 12.4 mg THC/24.8 mg CBD per day for up to 13 months, with no reported problems related to the treatment and limited adverse drug reactions. Clinical scores showed a marked improvement that was stable over time, deprescription of other medications, and care facilitated. The pharmacokinetic evaluation showed an expected slight reduction in the enzymatic activity of CYP1A2 and CYP2C19. A long-term THC/CBD (1:2) medication can be administered safely and with overall positive clinical improvement to poly medicated older adults with severe dementia and associated problems. The results must be confirmed in a randomized trial

    Clinical translation of the assets of biomedical engineering - a retrospective analysis with looks to the future

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    Introduction: Biomedical-engineering (BME) plays a major role in modern medicine. Many BME-based assets have been brought to clinical translation in the twentieth century, but translation currently stagnates. Here, we compare the impact of past and present scientific, economic and societal climates on the translation of BME-based assets, in order to provide the BME-community with incentives to address current stagnation. Areas covered: In the twentieth century, W.J. Kolff brought kidney dialysis, the total artificial heart, artificial vision and limbs to clinical application. This success raises the question whether Kolff and other past giants of clinical translation had special mind-sets, or whether their problem selection, their training, or governmental and regulatory control played roles. Retrospective analysis divides the impact of BME-based assets to clinical application into three periods: 1900-1970: rapid translation from bench-to-bedside, 1970-1990: new diseases and increased governmental control, and the current translational crisis from 1990 onward. Expert opinion: Academic and societal changes can be discerned that are concurrent with BME's translational success: mono-disciplinary versus multi-disciplinary training, academic reward systems based on individual achievements versus team achievements with strong leadership, increased governmental and regulatory control, and industrial involvement. From this, recommendations can be derived for accelerating clinical translation of BME-assets

    Nucleoplasmic LAP2 alpha-lamin A complexes are required to maintain a proliferative state in human fibroblasts

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    In human diploid fibroblasts (HDFs), expression of lamina-associated polypeptide 2 (LAP2) upon entry and exit from G0 is tightly correlated with phosphorylation and subnuclear localization of retinoblastoma protein (Rb). Phosphoisoforms of Rb and LAP2 are down-regulated in G0. Although RbS780 phosphoform and LAP2 are up-regulated upon reentry into G1 and colocalize in the nucleoplasm, RbS795 migrates between nucleoplasmic and speckle compartments. In HDFs, which are null for lamins A/C, LAP2 is mislocalized within nuclear aggregates, and this is correlated with cell cycle arrest and accumulation of Rb within speckles. Nuclear retention of nucleoplasmic Rb during G1 phase but not of speckle-associated Rb depends on lamin A/C. siRNA knock down of LAP2 or lamin A/C in HDFs leads to accumulation of Rb in speckles and G1 arrest, probably because of activation of a cell cycle checkpoint. Our results suggest that LAP2 and lamin A/C are involved in controlling Rb localization and phosphorylation, and a lack or mislocalization of either protein leads to cell cycle arrest in HDFs

    Both lamin A and lamin C mutations cause lamina instability as well as loss of internal nuclear lamin organization.

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    We have applied the fluorescence loss of intensity after photobleaching (FLIP) technique to study the molecular dynamics and organization of nuclear lamin proteins in cell lines stably transfected with green fluorescent protein (GFP)-tagged A-type lamin cDNA. Normal lamin A and C proteins show abundant decoration of the inner layer of the nuclear membrane, the nuclear lamina, and a generally diffuse localization in the nuclear interior. Bleaching studies revealed that, while the GFP-tagged lamins in the lamina were virtually immobile, the intranuclear fraction of these molecules was partially mobile. Intranuclear lamin C was significantly more mobile than intranuclear lamina A. In search of a structural cause for the variety of inherited diseases caused by A-type lamin mutations, we have studied the molecular organization of GFP-tagged lamin A and lamin C mutants R453W and R386K, found in Emery–Dreifuss muscular dystrophy (EDMD), and lamin A and lamin C mutant R482W, found in patients with Dunnigan-type familial partial lipodystrophy (FPLD). In all mutants, a prominent increase in lamin mobility was observed, indicating loss of structural stability of lamin polymers, both at the perinuclear lamina and in the intranuclear lamin organization. While the lamin rod domain mutant showed overall increased mobility, the tail domain mutants showed mainly intranuclear destabilization, possibly as a result of loss of interaction with chromatin. Decreased stability of lamin mutant polymers was confirmed by flow cytometric analyses and immunoblotting of nuclear extracts. Our findings suggest a loss of function of A-type lamin mutant proteins in the organization of intranuclear chromatin and predict the loss of gene regulatory function in laminopathies
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