Publications by authors named "Bock N"

A recursive algorithm for the inverse factorization S(-1)=ZZ(*) of Hermitian positive definite matrices S is proposed. The inverse factorization is based on iterative refinement [A.M.

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Manganese overexposure in non-human primates and humans causes a neurodegenerative disorder called manganism thought to be related to an accumulation of the metal in the basal ganglia. Here, we assess changes in the concentration of manganese in regions of the brain of a non-human primate (the common marmoset, Callithrix jacchus) following four systemic injections of 30 mg/kg MnCl2 H2O in the tail vein using T1-weighted magnetic resonance imaging (MRI) and compare these to changes in the rat following the same exposure route and dose. The doses were spaced 48 h apart and we imaged the animals 48 h after the final dose.

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We investigated the use of manganese-enhanced MRI (MEMRI) with fractionated doses as a way to retain the unique properties of manganese as a neuronal contrast agent while lessening its toxic effects in animals. First, we followed the signal enhancement on T1-weighted images of the brains of rats receiving 30 mg/kg fractions of MnCl2 . 4H2O every 48 h and found that the signal increased in regions with consecutive fractionated doses and ultimately saturated.

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The opportunities for human immunodeficiency virus (HIV) care and treatment created by new treatment initiatives promoting universal access are also creating unprecedented opportunities for persons with HIV-associated immunosuppression to be exposed to patients with infectious tuberculosis (TB) within health care facilities, with the attendant risks of acquiring TB infection and developing TB disease. Infection control measures can reduce the risk of Mycobacterium tuberculosis transmission even in settings with limited resources, on the basis of a 3-level hierarchy of controls, including administrative or work practice, environmental controls, and respiratory protection. Further research is needed to define the most efficient interventions.

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The magnetic ordering of a series of samples consisting of ultrathin Fe layers embedded in Pd was investigated using the magneto-optical Kerr effect. The samples consisted of a single Fe layer with nominal thickness 0.2≤d(Fe)≤1.

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Mouse models are crucial for the study of genetic factors and processes that influence human disease. In addition to tools for measuring genetic expression and establishing genotype, tools to accurately and comparatively assess mouse phenotype are essential in order to characterize pathology and make comparisons with human disease. MRI provides a powerful means of evaluating various anatomical and functional changes and hence is growing in popularity as a phenotypic readout for biomedical research studies.

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Impaired cognitive, memory, or motor performance is a distinguishing characteristic of neurological diseases. Although these symptoms are frequently the most evident in human patients, additional markers of disease are critical for proper diagnosis and staging. Noninvasive neuroimaging methods have become essential in this capacity and provide means of evaluating disease and tracking progression.

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Objective: The aim of this retrospective pilot study was to analyze and compare the short-term and long-term changes of Herbst treatment in Class II division 1 subjects of the retrognathic and prognathic facial type.

Materials And Methods: The subject material comprised 10 retrognathic (mean SNA = 74.5 degrees, SNB = 70.

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Protein-carbohydrate interactions are believed to be important in many biological processes involving cellular communication. Although many of the experimental approaches for studying protein-carbohydrate interactions are similar to those commonly employed in protein-protein interactions, several important aspects have to be taken into account in binding assays with lectin-like receptors such as Siglecs, sialic acid-recognizing immunoglobulin-like lectins. This chapter describes experimental approaches using solid-phase assays with sialylated targets and complexed Siglec Fc-chimeras for binding studies or competitive inhibition assays.

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High-grade gliomas are devastating brain tumors associated with a mean survival of <50 weeks. Two of the most common genetic changes observed in these tumors are overexpression/mutation of the epidermal growth factor receptor (EGFR) vIII and loss of PTEN/MMAC1 expression. To determine whether somatically acquired EGFRvIII expression or Pten loss accelerates high-grade glioma development, we used a previously characterized RasB8 glioma-prone mouse strain, in which these specific genetic changes were focally introduced at 4 weeks of age.

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Setting: A large, urban human immunodeficiency virus (HIV) voluntary counseling and testing (VCT) center in Kampala, Uganda.

Objective: Tuberculosis (TB) is a leading cause of morbidity and mortality in persons with HIV infection in sub-Saharan Africa. Intensified TB case finding and use of isoniazid preventive therapy (IPT) for latent infection reduces the burden of TB, but few programs have been implemented due to concerns about feasibility.

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Magnetic resonance imaging and computer image analysis in human clinical studies effectively identify abnormal neuroanatomy in disease populations. As more mouse models of neurological disorders are discovered, such an approach may prove useful for translational studies. Here, we demonstrate the effectiveness of a similar strategy for mouse neuroscience studies by phenotyping mice with the cerebellar deficient folia (cdf) mutation.

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Considerable progress has been made in adapting existing and developing new technologies to enable increasingly detailed phenotypic information to be obtained in embryonic and newborn mice. Sophisticated methods for imaging mouse embryos and newborns are available and include ultrasound and magnetic resonance imaging (MRI) for in vivo imaging, and MRI, vascular corrosion casts, micro-computed tomography, and optical projection tomography (OPT) for postmortem imaging. In addition, Doppler and M-mode ultrasound are useful noninvasive tools to monitor cardiac and vascular hemodynamics in vivo in embryos and newborns.

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Cardiac MR imaging in small animals presents some difficulties due to shorter cardiac cycles and smaller dimensions than in human beings, but prospectively gated techniques have been successfully applied. As with human imaging, there may be certain applications in animal imaging for which retrospective gating is preferable to prospective gating. For example, cardiac imaging in multiple mice simultaneously is one such application.

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Methylphenidate (MPH) is the most commonly used drug to treat attention deficit/hyperactivity disorder (ADHD) in children effectively and safely. In spite of its widespread application throughout one of the most plastic and sensitive phases of brain development, very little is known to date about its long-term effects on brain structure and function. Hence, this short review updates the influence of MPH on brain development, since recent human and animal studies suggest that MPH alters the dopaminergic system with long-term effects beyond the termination of treatment.

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We developed a live high-field multiple-mouse magnetic resonance imaging method to increase the throughput of imaging studies involving large numbers of mice. Phantom experiments were performed in 7 shielded radiofrequency (RF) coils for concurrent imaging on a 7 Tesla MRI scanner outfitted with multiple transmit and receive channels to confirm uniform signal-to-noise ratio and minimal ghost artifacts across images from the different RF coils. Grid phantoms were used to measure image distortion in different positions in the coils.

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With the enormous and growing number of experimental and genetic mouse models of human disease, there is a need for efficient means of characterizing abnormalities in mouse anatomy and physiology. Adaptation of magnetic resonance imaging (MRI) to the scale of the mouse promises to address this challenge and make major contributions to biomedical research by non-invasive assessment in the mouse. MRI is already emerging as an enabling technology providing informative and meaningful measures in a range of mouse models.

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Protein-protein interaction maps provide a valuable framework for a better understanding of the functional organization of the proteome. To detect interacting pairs of human proteins systematically, a protein matrix of 4456 baits and 5632 preys was screened by automated yeast two-hybrid (Y2H) interaction mating. We identified 3186 mostly novel interactions among 1705 proteins, resulting in a large, highly connected network.

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Interactions of the serotonergic and noradrenergic system at different sites of the brain may be important for efficacy and side effects of antidepressant drugs. Further, serotonin and noradrenaline play a critical role in the development of neurons during brain maturation. To gain further insight how brain maturation and the two monoaminergic systems are influenced by drug treatment during early postnatal development, this animal study investigated possible effects on the noradrenaline and serotonin transporter density of the frontal cortex very early in postnatal life.

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Human immunodeficiency virus (HIV) infection is the most powerful known risk factor for progression from latent infection with Mycobacterium tuberculosis to active tuberculosis (TB) disease. The worldwide HIV epidemic has affected TB in every aspect: immunopathology, epidemiology, diagnosis, treatment, and prevention. Of the 42 million people infected with HIV worldwide, more than a quarter of them are also infected with TB, and most live in countries with limited resources for health care in Africa and Asia.

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High-resolution magnetic resonance imaging is emerging as a powerful tool for phenotyping mice in biologic studies of genetic expression, development, and disease progression. In several applications, notably random mutagenesis trials, large cohorts of mice must be examined for abnormalities that may occur in any part of the body. In the aim of establishing a protocol for imaging multiple mice simultaneously in a standardized high-throughput fashion, this study investigates variations of a three-dimensional fast spin-echo sequence that implements driven equilibrium, modified refocusing, and partial excitation pulses.

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Background: Recently, a short-course treatment using 60 daily doses of rifampin and pyrazinamide was recommended for latent tuberculosis (TB) infection (LTBI).

Study Objectives: To determine the acceptability, tolerability, and completion of treatment.

Design: Observational cohort study.

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Background: The benzamide tiapride, a selective dopamine D2/D3-receptor antagonist, can be used effectively in children to treat tic disorders and stuttering. Tiapride is a clinically safe substance (even during long-term treatment and when given to young children). Unfortunately, its probable effects on general brain development and the maturation of the dopaminergic system have not been investigated.

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The use of mice to study models of human disease has resulted in a surge of interest in developing mouse MRI. The ability to take 3D, high-resolution images of live mice allows significant insight into anatomy and function. However, with imaging times on the order of hours, high throughput of specimens has been problematic.

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Setting: From 1993 through 1998, 1846 cases of multidrug-resistant tuberculosis (MDR-TB) were reported in the United States. Costs associated with MDR-TB are likely to be much higher than for drug-susceptible tuberculosis due to longer hospitalization, longer treatment with more expensive and toxic medications, greater productivity losses, and higher mortality.

Objective: To measure the societal costs of patients hospitalized for MDR-TB.

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